bluuebunny/crossref_metadata_2025 huggingface dataset:
Extracellular polysaccharides do not inhibit the reaction between Streptococcus mutans and its specific immunoglobulin G (IgG) or penetration of the IgG through S. mutans biofilm
Authors: Zhu M. , Takenaka S. , Sato M. , Hoshino E.
Published: March 2003

The present study investigated whether extracellular polysaccharides inhibit reaction between Streptococcus mutans and its specific immunoglobulin G (IgG) and penetration of the IgG through S. mutans biofilm. The planktonic organisms with or without extracellular polysaccharides were prepared, incubated with rabbit IgG against whole cell of S. mutans and fluorescein isothiocyanate (FITC)‐conjugated goat affinity purified antibody to rabbit IgG. Biofilms with or without extracellular polysaccharides were formed on cover glasses and incubated with rabbit IgG against S. mutans and FITC‐conjugated goat antibody to rabbit IgG. Then, biofilms were stained with propidium iodide. The amount of specific IgG binding on S. mutans was determined by FITC intensity with a fluorescence microplate reader. The penetration of IgG through biofilms was determined by confocal laser scanning microscopy. The results showed that the fluorescence intensity of FITC in planktonic organisms with extracellular polysaccharides was similar to that in planktonic organisms without extracellular polysaccharides, indicating that extracellular polysaccharides did not inhibit the reaction between S. mutans and its specific IgG. Although biofilms of S. mutans with extracellular polysaccharides were much thicker and denser than those without extracellular polysaccharides, the speed with which IgG penetrated through both of the biofilms did not differ significantly, suggesting that penetration of IgG through S. mutans biofilm was not affected by extracellular polysaccharides.
Immunoglobulin G response of periodontitis patients to Porphyromonas gingivalis capsular carbohydrate and lipopolysaccharide antigens
Authors: Sims T. J. , Schifferle R. E. , Ali R. W. , Skaug N. , Page R. C.
Published: March 2003

Porphyromonas gingivalis clonal types that participate in periodontal infections express serologically distinct surface antigens. This investigation sought to determine whether serum antibodies titers against the serotype‐specific capsular carbohydrate K antigen and lipopolysaccharide antigens of P. gingivalis might reveal which serotypes are most likely to be responsible for subgingival infections in subjects with adult periodontitis. Immunoglobulin G (IgG) titers to purified K antigen and lipopolysaccharide from different P. gingivalis strains were measured by ELISA for 28 healthy controls and 51 patients with periodontal pockets known to be infected with genetically and serologically distinct P. gingivalis clonal types. Titers to purified K antigen from strains W50, HG184, A7A1–28, 49417, HG1690 and HG1691, representing serotypes K1‐K6, respectively, and lipopolysaccharide from strains 381, HG1691 and W50, representing serotypes O1–O3, respectively, were measured for all subjects. Chi‐square likelihood ratios, Mann‐Whitney tests and receiver‐operating characterstic sensitivity–specificity plots were used to compare the accuracy with which titer results for different target antigens classified subjects with or without disease. Results from assays targeting K2, K3, K4, K5, O1 and O2 generally gave poor diagnostic accuracy, whether evaluated separately or as summed titer pairs corresponding to the K/O combinations actually expressed by the target antigen parent strains. Exceptions were O3 (from W50) and K5+O2 (both from HG1690), which gave moderate accuracy in classifying subjects. In contrast, highly significant diagnostic accuracy was achieved using individual K1 (W50) and K6 (HG1691) titer data and K1+O3 (W50) and K6+O2 (HG1691) titer sum values. These observations suggest that P. gingivalis clonal types expressing K/O serotypes matching those of W50 (K1/O3) and HG1691 (K6/O2) are more likely than others to participate in periodontal infections in adult periodontitis patients and thus are more likely than others to express relevant virulence factors.
Cytomegalovirus periodontal presence is associated with subgingival Dialister pneumosintes and alveolar bone loss
Authors: Slots J. , Sugar C. , Kamma J. J.
Published: March 2003

Destructive periodontal disease is associated with human cytomegalovirus (HCMV), Epstein‐Barr type 1 virus (EBV‐1) and other members of the Herpesviridae family as well as with various gram‐negative anaerobic bacteria, including the Dialister pneumosintes species. This study aimed to determine possible interrelationships between periodontal HCMV, EBV‐1, herpes simplex virus and D. pneumosintes, and relate the microbiological findings to periodontitis clinical status. Sixteen subjects each contributed paper point samples from two progressing and two stable periodontitis lesions, as determined by ongoing loss of probing attachment. Polymerase chain reaction methodology was used to identify the study herpesviruses and D. pneumosintes. Chi‐squared tests, Fisher exact tests and multivariate logistic regression were employed to identify statistical associations among herpesviruses, bacteria and clinical variables. HCMV, and no other virus or combination of viruses, was positively associated with the presence of D. pneumosintes, and the relationship was specific for individual periodontitis sites with no detectable subject effect. D. pneumosintes was in turn positively associated with periodontal pocket depth and disease‐active periodontitis. When the average percentage of alveolar bone loss in all teeth was treated as a response, HCMV remained significant even after D. pneumosintes was included in the model, suggesting that both HCMV and D. pneumosintes affected bone loss or, alternatively, HCMV affected factors not studied that themselves can induce bone loss. We hypothesize that periodontal HCMV sets the stage for subgingival proliferation of D. pneumosintes and subsequent periodontal disease progression. Studies on herpesviral–bacterial interactions may hold great promise for delineating important etio‐pathogenic aspects of destructive periodontal disease.
Cutaneous lymphocyte‐associated antigen expression in children with atopic dermatitis and non‐atopic healthy children
Authors: Campbell D. E. , Kemp A. S.
Published: March 2003

Cutaneous lymphocyte‐associated antigen (CLA) is a cell surface glycoprotein which has been implicated in the homing of lymphocytes to cutaneous sites. It is postulated to play an important role in T‐cell migration to skin in atopic dermatitis; however, the expression of CLA in both normal children and children with atopic dermatitis has not been extensively studied. If CLA expression on T cells were important in the traffic of lymphocytes to atopic dermatitis skin lesions, it might be expected that the proportion of CLA+ T cells in unstimulated peripheral blood from children with atopic dermatitis would be elevated. We have examined the proportion of CLA+ T cells in children with atopic dermatitis and non‐atopic age‐matched controls. The proportion of CLA+ T cells in non‐atopic children was highly associated with and increased with increasing age (r = 0.88, p < 0.001). There was no difference between the proportion of T cells expressing CLA in the unstimulated PBMC from children with severe or mild/moderate atopic dermatitis and age‐matched non‐atopic controls (p = 0.18, p = 0.3, respectively). Despite this, children with atopic dermatitis did show evidence of perturbation of CLA expression, as unlike the non‐atopic children the proportion of CLA+ T cells in the atopic children did not correlate with age. These findings suggest that while CLA expression may play a role in atopic dermatitis, other as yet undefined surface markers are likely to principally determine the migration of T cells to skin in atopic dermatitis.
Nasal peak inspiratory flow through Turbuhaler® in children with symptomatic rhinitis and in healthy children
Authors: Van Zoest J. G. C. M. , Van Der Weij A. M. , Duiverman E. J. , Akerlund A. , Kouwenberg J. M.
Published: March 2003

Topical treatment of allergic or vasomotor rhinitis is possible by means of pressurized metered dose inhalers, aqueous spray, or dry powder inhalers. In children, little is known about nasal drug delivery by dry powder inhalation. The airflow through the device is critical for the drug release and a sufficient nasal inspiratory flow is needed for intranasal drug delivery from a dry powder inhaler. In order to investigate from what age children with allergic or vasomotor rhinitis can reliably use such a device, device‐dependent nasal peak inspiratory flow (DnPIF) was measured. The maximal DnPIF was measured in children aged 4–13 years making use of a dry powder inhaler (Turbuhaler®) connected to a spirometer (Vitalograph®). In the clinically relevant context, instructions from the doctor and one week's use of a Turbuhaler at home were found to be sufficient to obtain a good inhalation technique and were shown to improve DnPIF at least as effectively as visual feedback training at the clinic. Children with rhinitis, as well as healthy children from the age of 6 years, were able to generate a DnPIF sufficient to obtain a reliable nasal delivery of a dry powder drug dose. DnPIF values correlated with age. Consequently, a recommendation to use a nasal Turbuhaler from the age of 6 for topical drug delivery in the treatment of allergic or vasomotor rhinitis seems reasonable.
Effect of montelukast on exhaled NO in asthmatic children exposed to relevant allergens
Authors: Piacentini Giorgio L. , Peroni Diego G. , Del Giudice Michele Miraglia , Bodini Alessandro , Costella Silvia , Vicentini Lucia , Boner Attilio L.
Published: March 2003

The level of exhaled nitric oxide (FENO) is increased in house dust mite (HDM)‐sensitized asthmatic children after exposure to HDM antigen, and inhaled steroids can prevent this increase. The aim of this study was to evaluate whether montelukast could prevent an increase in FENO levels in allergic asthmatic children after a brief period of exposure to relevant allergens. Sixteen children were evaluated at the residential house ‘Istituto Pio XII’ (Misurina, Bellunio, Italy) in the Italian Alps, a dust mite‐free environment. FENO levels were evaluated before (t0) and immediately after (t1) the children were exposed to HDM allergens for 2 weeks in their homes at sea level. No significant difference in FENO was observed in the fluticasone‐treated group of children after 2 weeks at sea level. In the group treated with montelukast, an increase in FENO was observed between t0 and t1, which failed to reach statistical significance. These preliminary data suggest that oral montelukast could be effective in preventing the relapse in airway inflammation in allergic asthmatic children who are occasionally exposed to relevant allergens for a short period of time.
Living donor liver transplantation in critically ill children
Authors: Casas Adela , Falkenstein , Kathleen , Gallagher , Mary , Dunn Stephen P.
Published: March 2003

Abstract: From December 1993, St Christopher’s Hospital for Children, Philadelphia, PA, USA has provided living donors the opportunity to donate a portion of their liver to children who are critically ill. This report evaluates the results of living donor liver transplants (LDLT) in critically ill children. We retrospectively reviewed the first 22 LDLT at our institution and compared the patient and graft survival of the nine critically ill children with the 13 stable children. Twenty‐two LDLT have been performed at our institution between December 1993 and October 1997. Nine of 22 transplants [United Network for Organ Sharing (UNOS) Status I] were performed in children who were critically ill. Thirteen of the LDLT (UNOS Status II and III) were performed on stable children either in the hospital or admitted electively from home. The median weight and age at the time of transplant were 7 kg (range 4.6–54.5 kg) and 16 months (range 3 months–12 yr), respectively, and there was no statistical difference between the two groups. In critically ill children the 1‐yr allograft and patient survival was 66% and 89%, respectively, exceeding the published results from UNOS for patients on life support (59.5% graft and 69.7% patient survival at 1 yr). One‐yr allograft and patient survival in the stable children was 92.3% and 100%, respectively. All living donors are alive and well with normal liver function. In conclusion, our results show that LDLT is a viable approach for transplantation in critically ill children with liver failure and should be offered to potential donors.
Correlation between allograft survival and chimeric state after bone marrow infusion in rat small bowel transplantation
Authors: Bakonyi Neto Alexandre , Ricordi , Camillo , Feo , Claudio F. , Porcu , Alberto , Misiakos , Evangelos P. , Gandia , Carlos , Ruiz , Phillip , Bertho , Mariana , Carreno , Manuel , Esquenazi , Violet , Miller , Joshua , Tzakis Andreas G.
Published: March 2003

Abstract: Methods to enhance natural microchimerism, which occurs after any successful organ transplant, are currently explored using unmodified donor bone marrow both in experimental and in clinical trials. Because of the potential immunomodulatory effects of donor bone marrow cells, we performed this study to evaluated the effect of single and multiple donor‐specific bone marrow infusions (DSBMI) on chimerism and small bowel allograft survival in a fully histoincompatible rat model. Forty‐five male DA rats and 45 female Lewis rats were used as donors and recipients, respectively, for a heterotopic small bowel transplant. Animals were separated into 10 groups according to the number of bone marrow infusions and immunosuppressive protocol used. Control groups (groups 1 and 2) did not receive any bone marrow infusion, groups 3 and 4 received one infusion at day 0 (150 × 106 cells), groups 5 and 6 received two infusions at days 0 and 4 (75 × 106 cells each), groups 7 and 8 received two infusions at days 4 and 10 (75 × 106 cells each), and groups 9 and 10 received five infusions at days 4, 10, 15, 20 and 25 (30 × 106 cells each). Animals in groups 1, 3, 5, 7 and 9 were immunosuppressed with 0.5 mg/kg FK506 while the remaining groups were immunosuppressed with 1 mg/kg FK506, from day 0 to 4 after transplant. Every 15 days, the chimeric state was determined by flow cytometry in order to detect cells expressing DA rat class I antigen, and small bowel biopsies were obtained from ileostomies. Animals in all groups showed minimal to moderate acute rejection at day 15 after transplant, however, vascular rejection (vasculitis, arteritis) was observed in only bone marrow groups (100% in 0.5 mg/kg and 42.1% in 1 mg/kg FK506 groups). On day 30, 58.3% of bone‐marrow‐infused animals and 66.6% of controls showed severe acute and early chronic rejection. The chimeric levels varied from 0 to 12% after transplant and were significantly higher in bone‐marrow‐infused groups compared with controls (p < 0.05). We conclude that modulation of immune response with short‐course immunosuppression and a single or multiple DSBMI did not improve allograft or recipient survival. The inability to achieve a stable chimeric state did not allow us to determine the effect of chimerism on graft and recipient survival after small bowel transplantation
Quantitation of peripheral blood cytomegalovirus DNA for monitoring recurrent cytomegalovirus retinitis in pediatric solid organ transplant recipients
Authors: Aw M. M. , Murugasu B. , Tan A. W. , Seah C. C. , Balakrishnan V. , Yap H. K.
Published: March 2003

Abstract:Cytomegalovirus (CMV) infection is a major concern following solid organ transplantation, especially in the pediatric population who remain at high risk of primary infection. CMV disease leads not only to increased patient and graft morbidity, but also to increased health care costs. This study describes the usefulness of a quantitative CMV polymerase chain reaction (PCR) technique for monitoring peripheral blood CMV DNA in pediatric recipients of kidney and liver allografts who had recurrent CMV retinitis. The incidence of CMV disease in 28 pediatric transplant recipients was 28.6%, one‐half of whom developed retinitis. Two of these patients had recurrent retinitis on cessation of anti‐viral treatment. A peripheral blood CMV DNA copy number of ≥ 500/µg of DNA was associated with recrudescence of the retinitis in these patients. We conclude that the measurement of peripheral blood CMV DNA by PCR is a useful tool for the surveillance of disease resolution and recurrence. This is particularly important in patients with CMV retinitis, who may remain asymptomatic for a period of time, despite recurrences.
Administration of recombinant human granulocyte‐macrophage colony‐stimulating factor to children undergoing allogeneic marrow transplantation: A prospective, randomized, double‐masked,placebo‐controlled trial
Authors: Trigg Michael E. , Peters Charles , Zimmerman M. Bridget
Published: March 2003

Abstract: Granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) was administered to 40 pediatric patients undergoing partially matched related, or closely matched unrelated, allogeneic marrow transplants. This trial was set up in a prospective, randomized, double‐masked, placebo‐controlled manner to establish if the administration of GM‐CSF to such patients enhanced neutrophil recovery in this allogeneic transplant setting. The GM‐CSF group had a significantly shorter time to neutrophil recovery to > 500 × 109 cells/L (15 days) than the placebo group (p = 0.0036). In addition, the GM‐CSF group had a significantly shorter neutrophil recovery time to > 1000 × 109 cells/L (18 days) than the placebo group (p = 0.0053). The primary objective of this study was met by showing that GM‐CSF enhanced neutrophil recovery in this allogeneic setting. However, within the study group of patients, there was no effect of GM‐CSF on the incidence or severity of graft‐vs.‐host disease (GvHD), one of the secondary end‐points of the study. With regard to the other secondary end‐points, there was no effect of GM‐CSF on marrow cellularity, duration of systemic antibiotics given for real infections or as prophylaxis to prevent infections, risk of significant infections (as defined by systemic culture of virus, fungus, or bacteria), and duration or cost of hospitalization, platelet recovery, and nutritional support. With the secondary end‐points, it will be necessary to study larger numbers of pediatric patients to identify differences that are small in this study group. In conclusion, GM‐CSF can be safely administered to children with few, if any, significant side‐effects. Additional work remains to facilitate earlier discharge of patients and decreased antibiotic usage, to offset the cost of using a neutrophil growth factor.
Fatal deterioration of neurological disease after orthotopic liver transplantation for valproic acid‐induced liver damage
Authors: Kayihan Nilüfer , Nennesmo Inger , Ericzon Bo‐Göran , Németh Antal
Published: March 2003

Abstract: We describe a 12‐year‐old girl with an early onset neurologic disease of slow progressiveness and electro‐encephalography showing epileptic activity. The girl developed fulminant liver failure 5 months after the start of valproic acid treatment. Repeated mitochondrial assays failed to prove a mitochondrial disorder, but muscle biopsies were slightly pathological. Liver histology indicated acute‐on‐chronic liver disease. Six weeks after a successful orthotopic liver transplantation her neurological condition deteriorated rapidly, soon leading to generalized cortical disease and death. Post‐mortem brain examination showed advanced central nervous destruction. We suggest that this is a late‐onset Huttenlocher variant of Alpers’ syndrome, where fulminant liver failure can be triggered by valproic acid, and orthotopic liver transplantation can subsequently trigger a fatal neurologic deterioration. Our case illustrates that when a referral center receives a previously unknown patient with hepatocellular insufficiency, it might be impossible to differentiate between fulminant vs. acute‐on‐chronic liver failure, and the decision whether to perform a liver transplantation or not would become difficult.
A decade of living donor transplantation in North American children: The 1998 Annual Report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) *
Authors: McDonald Ruth , Donaldson Lynn , Emmett Lea , Tejani Amir
Published: March 2003

Abstract:This report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) covers the years 1987–1997, and analyzes data on 2904 living donor (LD) transplants performed in 2779 patients. Since 1991, approximately 300 LD transplants have been performed each year at the participating centers of the NAPRTCS. Caucasian children account for 72% of all LD recipients while African–American children constitute only 11%. There has been a gradual decline in the number of transplants performed in children under the age of 6 years from a peak of 30% in 1987, to 21% in 1997. Preoperative calcineurin inhibitor therapy has dropped from 71% in 1987 to 38% in 1997. Through 1996, at six months post‐transplant 97% of recipients were receiving prednisone, 88% were maintained on cyclosporin A, and 79% were receiving azathioprine. Of patients transplanted in 1997, 47% are maintained on mycophenolate and 10% are maintained on tacrolimus. By day 15, 20% of index transplant patients have had an acute rejection and by the end of the first year 47% have had a rejection episode. Among patients transplanted in 1995–1996, 40% had a rejection in the first year. Nine per cent of rejection episodes are irreversible in children under 2 years of age and 5% of the episodes are irreversible in 2–5‐year‐old children. Estimated graft survival probability at 1 year is 91%, at 3 years it is 84% and at 5 years it is 78.5%. Rejection accounts for 33% of graft loss and recurrence constitutes another 10%. Influential prognostic variables for graft survival are race (African–American vs. others, relative risk (RR) = 2.0, p < 0.001), > 5 random transfusions (RR = 1.6, p < 0.001), T‐cell induction therapy (RR = 0.78, p = 0.01), and later year of entry (1989–1990 vs. 1994–1995, RR = 0.95, p = 0.004). Patient survival at 1 and 3 years was 97% and 96.5%, respectively, however, the 3‐year patient survival of children under 2 years was 89%. The mean height deficit at baseline (n = 2677) was − 1.86, at 1 year post‐transplant (n = 1459) it was − 1.80, and at 5 years post‐transplant (n = 592) it was − 2.06. This report, devoted specifically to LD pediatric transplants, raises issues regarding the use of immunosuppression such as preoperative calcineurin inhibitors and T‐cell antibodies. Studies to address the high incidence of chronic rejection and recurrence of original disease are necessary. Additional areas of concern are the high infant mortality and continued growth retardation post‐transplantation.
Living‐related pediatric renal transplants:  A single‐center experience from a developing country
Authors: Rizvi S. A. H. , Naqvi S. A. A. , Hussain Z. , Hashmi A. , Akhtar F. , Zafar M. N. , Hussain M. , Ahmed E. , Kazi J. I. , Hasan A. S. , Khalid R. , Aziz S. , Sultan S.
Published: March 2003

Abstract:We retrospectively analyzed the results of 75 living‐related pediatric renal transplants performed at our center between January 1986 and December 1999. The major causes of end‐stage renal disease (ESRD) were glomerulonephritis (26%) and nephrolithiasis (16%), while the etiology was unknown in 50%. The mean age of the recipients was 12 yr (range 6–17 yr) and that of the donors was 39 yr (range 20–65 yr). The majority (73%) of donors were parents. Eighty five per cent of donors were one‐haplotype matched and the rest identical. Immunosuppression was based on a triple drug regimen. Thirty per cent of recipients were rapid metabolizers of cyclosporin A (CsA) (area under the curve [AUC]: < 6,000 ng/mL/h), while 16% were slow metabolizers (AUC: > 8,000 ng/mL/h). Forty three (57%) children encountered 59 rejection episodes, the majority of which (59%) were recorded in the first month post‐transplant. Seventy‐four per cent of the rejection episodes were steroid sensitive and the rest, except two, were resolved by therapy with antithymocyte globulin (ATG) or orthoclone thymocyte 3 (OKT3). After a mean follow‐up of 37 months, 17 (22%) grafts had chronic rejection and 76% of these recipients had previously experienced acute rejection episodes. The overall infection rate was high, necessitating two hospital admissions/patient/year. The majority (53%) of the infections were bacterial. Urinary tract infections (UTIs) were seen in 17 (23%) recipients. Twelve of these had ESRD as a result of stone disease and eight grafts were lost because of UTIs. Eight per cent of recipients developed tuberculosis (TB), and extra‐pulmonary lesions were seen in 50%. Surgical complications were encountered in eight patients. Free medication to all recipients and parental support ensured a compliance rate of 93%. Baseline growth deficit was seen in children of the two groups studied (the 6–12 yr and 13–17 yr age‐groups), withZ‐scores of – 2.39 and – 2.12, respectively. No growth catch‐up was observed at 12 and 24 months in either group. Post‐donation complications were seen most commonly in donors > 50 yr of age and included: proteinuria (> 300 mg/24 h, four patients), hypertension (three patients), and diabetes (one patient). Twenty‐four grafts were lost, 54% as a result of immunological and the rest as a result of non‐immunological causes, and 17 recipients died during the follow‐up period. Infections were the main cause of patient and graft loss. Overall 1‐ and 5‐yr graft and patient survival rates were 88% and 65%, and 90% and 75%, respectively.
Orthotopic liver transplantation for acute liver failure secondary to autoimmune hepatitis in a child with autoimmune polyglandular syndrome type 1
Authors: Smith Dominic , Stringer Mark D. , Wyatt Judy , O'Meara Moira , Davison Suzanne , Cheetham Tim D. , McClean Patricia
Published: March 2003

Autoimmune polyglandular syndrome type 1 (APS‐1) is an autosomal‐recessive condition characterized by hypoparathyroidism, autoimmune Addison's disease, and chronic mucocutaneous candidiasis. Autoimmune hepatitis develops in 10–20% of affected patients and has a variable course ranging from asymptomatic chronic liver disease to lethal fulminant hepatic failure. Liver transplantation has been documented previously in only two patients. We report a 14‐yr‐old boy with APS‐1 who developed acute liver failure secondary to associated autoimmune hepatitis. He did not respond to corticosteroid therapy and was successfully treated with an orthotopic liver transplant.
Stimulated cortisol secretion is not correlated with prednisone dose or with steroid side‐effects in children after renal transplantation
Authors: Revermann T. , Soergel M. , Hellinger A. , Klaus G.
Published: March 2003

Abstract:Impairment of adrenocortical function and other adverse effects have to be considered whenever corticosteroids are applied for a prolonged period of time. We hypothesized that the assessment of adrenal function with adrenocortiocotropin (ACTH) stimulation reflects the sensitivity to corticosteroids and would predict the development of side‐effects in pediatric patients on triple immunosuppression after renal transplantation.
Long‐term survival after liver transplantation in children with metabolic disorders
Authors: Kayler Liise K. , Merion Robert M. , Lee Samuel , Sung Randall S. , Punch Jeffrey D. , Rudich Steven M. , Turcotte Jeremiah G. , A. Campbell Darrell , Holmes Ronald , Magee John C.
Published: March 2003

Abstract:Background:Liver transplantation for inherited metabolic disorders aims to save the patient's life when the disorder is expected to progress to organ failure, and to cure the underlying metabolic defect.Methods: We retrospectively analyzed 146 pediatric liver transplants (28 metabolic; 118 non‐metabolic) performed between 1986 and 2000.Results: Twenty‐eight transplants were performed in 24 children with metabolic disease (8 females; 16 males; age range 3 months to 17 yr). Indications included α−1‐antitrypsin deficiency (n = 8), two cases each of hyperoxaluria type 1, Wilson's disease, hereditary tyrosinemia type I, citrullinemia, methylmalonic acidemia, and one case each of propionic acidemia, Crigler–Najjar syndrometype I, neonatal hemachromatosis, hemophilia B, Niemann–Pick disease type B, and cystic fibrosis. Eighteen transplants were whole organ grafts and 10 were lobar or segmental. Auxiliary liver transplants were performed in two patients and three received combined liver‐kidney transplants. There were three deaths from sepsis, two from chronic rejection, and one from fulminant hepatitis. Seven of 10 patients currently of school age are within 1 yr of expected grade and three who had pretransplant developmental delay have remained in special education. Actuarial survival rates at 5 and 10 yr are 78% and 68%, respectively, with mean follow‐up in excess of 5 yr. These results compare favorably to 100 pediatric patients transplanted for non‐metabolic etiologies (65% and 61%, respectively) (p= NS).Conclusions: Pediatric liver transplantation for metabolic disorders results in excellent clinical and biochemical outcome with long survival and excellent quality of life for most recipients.
Prevention of parenteral nutrition‐associated liver disease in children
Authors: Kaufman Stuart S.
Published: March 2003

Abstract: Liver injury is associated with parenteral nutrition therapy. Severity of injury varies from minimal and transient increases in liver‐related blood tests to biliary cirrhosis and liver failure. Severe parenteral nutrition‐related liver disease is usually confined to patients who have undergone massive intestinal resection. In these patients, early sepsis appears to cause initial liver injury, and recurring sepsis and inflammation, local or systemic, may result in its perpetuation and progression. Liver disease associated with parenteral nutrition is not necessarily related either to duration of parenteral nutrition or to delayed intestinal feeding. However, treatment includes enteral nutrition to promote enterohepatic circulation of bile acids and management of inflammation and sepsis, including control of intestinal bacterial overgrowth. Restriction of intravenous lipid emulsions may be important. The clinical picture of advanced liver failure related to short bowel syndrome differs from liver failure with an anatomically normal gastrointestinal tract. In the former, hyperbilirubinemia, hepatosplenomegaly, and functional hypersplenism dominate the clinical picture, and severe ascites and esophageal variceal hemorrhage are unusual. Early referral of these patients for intestinal and/or liver transplantation may provide the best chance for long‐term survival.
Effect of low temperatures on the activity of oxygen‐scavenging enzymes in two populations of the C4 grass Echinochloa crus‐galli
Authors: Hakam Nadia , Simon Jean‐Pierre , Vogelmann T. C.
Published: March 2003

To discriminate among possible mechanisms responsible for the differential response to cold temperatures among ecotypes of the C4 grass weed species Echinochloa crus‐galli (L.) Beauv., the specific activities of five oxygen‐scavenging enzymes responsible for the elimination or reduction of free radicals and hydrogen peroxide during cold‐induced photoinhibition were determined in 5‐week‐old plants of two populations of the species collected from sites of contrasting climates, Québec (QUE) and Mississippi (MISS). Enzyme activities were measured at temperatures ranging from 5 to 30°C. The specific activities of ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase were significantly higher in cold‐adapted QUE plants at low assay temperatures than in warm‐adapted MISS plants at the same temperature. The specific activities of superoxide dismutase assayed at 5 and 25°C were similar among plants of the two E. crus‐galli populations. Ascorbate concentrations were not different among plants of the two populations, suggesting that the observed differences in the specific activities of ascorbate peroxidase assayed at 5°C, truly reflect a better capacity of the QUE enzyme to reduce H2O2 to water at temperature conditions associated with the photoinhibitory process. The enhanced specific activity of four of the five oxygen‐scavenging enzymes measured in the cold‐adapted QUE population at low assay temperatures correlates with the syndrome of cold‐adapted features reported for plants of this population in earlier studies.
Availability of assimilates and formation of aroma compounds in apples as affected by the fruit/leaf ratio
Authors: Poll Leif , Rindom Anders , Toldam‐Andersen Torben Bo , Hansen Poul
Published: March 2003

Availability of assimilates in apple trees (Malus domestica cv. Jonagored) was affected by removing young fruits to obtain 3 ranges of fruit/leaf ratios with average values of 130, 268 and 381 fruits per kg leaf dry matter. Fruit analyses were carried out at fruit harvest and 4 times during a 3‐week ripening period. The analyses included detection of volatile aroma components from the juice by headspace gas chromatography. At a low fruit/leaf ratio, higher concentrations of total dry matter, soluble solid and titrateable acids were found. The flesh was also firmer, and ethylene development proceeded at a lower rate and reached a lower maximum value. Aroma compounds consisted of ca 20% esters, 73% alcohols and 6% C‐6 aldehydes. The production of butylacetate and hexylacetate, which were the dominating esters, peaked during the ripening period and was most pronounced at the lowest fruit/leaf ratios. At the last sampling date this was also the case for butanol, which was the dominating alcohol. Other esters and alcohols behaved similarly, while C‐6 aldehydes showed no significant differences in the fruit/leaf ratio. We suggest that the greater availability of assimilates when internal competition is relieved at a low fruit/leaf ratio causes increased accumulation of fatty acid aroma precursors and aroma compounds as well as of sugars, acids and other compounds in the fruits.
Gravitropic responses of the Avena coleoptile in space and on clinostats. III. Hypogravity effects on coleoptile curvatures
Authors: Karlsson Christina , Johnsson Anders , Chapman David K. , Brown Allan H.
Published: March 2003

The precise description of the gravitropic curvature response of plants is often difficult due to the presence of gravity when the response is recorded. Therefore, unambiguous results on the gravitropic reactions in differents segments of coleoptiles, the participation of auxin transport in the curvature development and the reactions to hypogravity stimulations can only be achieved in weightlessness. To answer these questions, curvatures of Avena coleoptiles at different distances from the apex were studied after transverse, hypogravity stimulations. The experiments were conducted in Spacelab on the Shuttle in earth orbit.

Test plants were cultivated on 1.0 g‐centrifuges in Spacelab. The stimulation accelerations, were between 0.1 and 1.0 g, and duration varied between 2 and 130 min. All plant responses were recorded in weightlessness by a video cassette recorder for analysis.

The gravitropic curvature started almost simultaneously in apical segments, and occurred later in the basal ones. After maximum response, the curvature in the top segments showed a clear autotropic reaction, that was not seen in the basal segments. Initial wrong‐way curvatures were recorded in the basal part of the coleoptiles at several g‐levels.

The further down along the coleoptile, the later the occurrence of the maximum gravitropic curvature of each segment. For example, after a stimulus of 25 g min the maxima appeared to travel down the coleoptile with a speed of about 50 mm h−1 in the upper and 20 mm h−1 in the lower part of the coleoptiles. It is concluded that the basipetal auxin transport can contribute only marginally to the gravitropic curvature pattern due to its much lower transport rate. Local reactions control the curvature pattern in each segment (even if the basipetal auxin transport must add to the reactions).

Extrapolations from stimulus response data curves allowed some determinations of threshold stimulation times for different segments along the coleoptiles. Data for the individual segments along the coleoptiles were not at variance with the reciprocity law.
Germination in spores of Dryopteris filix‐mas: Regulation of rhizoid elongation as a second phytochrome‐mediated response
Authors: Yatsuhashi Hiroko , Turnwald Stefan , Scheuerlein Robert
Published: March 2003

Spore germination in Dryopteris filix‐mas occurs via a cascade of cellular responses, and chlorophyll formation, mitosis or rhizoid elongation are commonly used as parameters to determine spore germination. Detailed investigations of these parameters led to the hypothesis that they are regulated by different, independent phytochrome‐mediated responses. This concept could be confirmed, as is described in this paper which demonstrates that perception of light via phytochrome occurs within two different phases separated in time. Presence of the far‐red absorbing phytochrome form, Pfr, for 36 h, induces chlorophyll formation and the first unequal cell division, by which a rhizoid initial and a protonemal initial are formed (first phytochrome‐mediated response). However, rhizoid elongation requires a second period of Pfr, presence (second phytochrome‐mediated response). There is a clear temporal distinction between the first and the second phytochrome‐mediated response with respect to the coupling of Pfr to the transduction chain; Pfr is unable to induce rhizoid growth until 60 h after the start of the first red irradiation. The effectivity of Pfr for inducing the second response shows an optimum at ca 96 h after the beginning of the presence of Pfr; thereafter, it declines slowly. The fluence‐response relationship and the presence of red/far‐red reversibility demonstrate that rhizoid elongation is a low‐fluence response mediated by phytochrome and is independent of the first phytochrome response.
The accumulation of trehalose in nodules of several cultivars of common bean (Phaseolus vulgaris) and its correlation with resistance to drought stress
Authors: Farías‐Rodríguez Rodolfo , Mellor Robert B. , Arias Carlos , Peña‐Cabriales Juan José
Published: March 2003

Nine cultivars of common bean were grown in the presence of a natural microflora without exogenous rhizobial inoculation. Nodules were harvested 30 days post planting (early flowering stage) and the presence of trehalose determined. Amounts present varied according to cultivar and were between 0.20 and 1.63 mg g−1 nodule dry weight. Rhizobial strains were isolated from the nodules of three selected cultivars (Canario 101, Flor de Mayo Bajio and Flor de Mayo 38). Trehalose levels in nodules produced after either mixed strain reinfection, or after axenic homologous reinfection or after axenic cross‐reinfection could be manipulated by applying drought stress. Mixed reinfection nodules from stressed plants accumulated between two and six times the trehalose concentration found in non‐stressed control plants. After axenic cross‐reinfection up to 48‐fold increases in nodule trehalose content were recorded during drought stress. Those cultivars exhibiting high nodule trehalose levels and/or a high degree of trehalose stimulation in response to drought stress also exhibited a high leaf relative water content and were also the most drought resistant. During drought stress nodule trehalase levels rose only slightly.
Light‐dependent changes of tomato glutamine synthetase in response to Pseudomonas syringae infection or phosphinothricin treatment
Authors: Pérez‐García Alejandro , de Vicente Antonio , Cantón Francisco R. , Cazorla Francisco M. , Codina Juan C. , García‐Gutiérrez Ángel , Cánovas Francisco M.
Published: March 2003

Glutamine synthetase (GS, EC 6.3.1.2), a key enzyme in nitrogen assimilation, was investigated in tomato (Lycopersicon esculentum Mill. cv. Hellfrucht Frühstamm) leaves infected with Pseudomonas syringae pv. tomato (Pst) or treated with the herbicide phosphinothricin (PPT), an irreversible inhibitor of GS. GS activity decreased markedly when Pst infection occurred in illuminated leaves, but only a slight decrease in relation to control leaves was observed under non‐photosynthetic conditions. In leaves treated with PPT, a rapid inhibition of GS activity was observed under all experimental conditions. When bacterial infection or herbicide treatment was carried out in the light, cytosolic GS (GS1) appeared as the predominant GS polypeptide; however, under non‐photosynthetic conditions GS2 remained the most abundant molecular GS species as occurs in non‐stressed plants. These results suggest a close correlation between the photosynthetic process and changes in the relative proportions of GS polypeptides during infection or herbicide treatment. Ammonium has been described as an inducer of GS genes, but as ammonium accumulated during all treatments, other light‐dependent factors could be involved in GS regulation of stressed leaves.
The spinach plasma membrane Ca2+ pump is a 120‐kDa polypeptide regulated by calmodulin‐binding to a terminal region
Authors: Olbe Malin , Sommarin Marianne
Published: March 2003

The spinach (Spinacia oleracea L.) leaf plasma membrane Ca2+‐ATPase is regulated by calmodulin (3‐fold stimulation) and limited proteolysis (trypsin; 4‐fold stimulation). The plasma membrane Ca2+‐ATPase was identified as a 120‐kDa polypeptide on western immunoblots using two different antibodies. During trypsin treatment the 120‐kDa band diminished and a new band appeared at 109 kDa. The appearance of the 109‐kDa band correlated with the increase in enzyme activity following trypsin treatment. The stimulations by calmodulin and trypsin were not additive, suggesting that the 109‐kDa polypeptide represents a Ca2+‐ATPase lackin a terminal fragment involved in calmodulin regulation. This was confirmed by 125I‐calmodulin overlay studies where calmodulin labeled the 120‐kDa band in the presence of Ca2+, while the 109‐kDa band did not bind calmodulin. The effects of calmodulin and limited proteolysis on ATP‐dependent accumulation of 45Ca2+ in isolated inside‐out plasma membrane vesicles were studied, and kinetical analyses performed with respect to Ca2+ and ATP. Calmodulin increased the Vmax. for Ca2+ pumping 3‐fold, and reduced Km for Ca2+ from 1.6 to 0.9 µM. The Km for ATP (11 µM) was not affected by calmodulin. The effects of limited proteolysis on the affinities for Ca2+ and ATP were similar to those obtained with calmodulin. Notably, however, limited proteolysis increased the Vmax. for Ca2+ pumping to a higher extent than calmodulin, indicating incomplete calmodulin activation, or removal of an additional inhibitory site by trypsin.
Role of phosphoenolpyruvate carboxylase in malate production by the developing barley aleurone layer
Authors: Macnicol Peter K. , Raymond Philippe
Published: March 2003

The pathway of malate synthesis in the developing aleurone layer of barley (Hordeum vulgare L. cv. Himalaya) was investigated. Malate formation did not occur under anoxia. Labelling with [2‐14C]acetate showed that the glyoxylate pathway was not a significant source of malate. The partitioning of glycolytic carbon flux at the branchpoint between phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) and pyruvate kinase (PK, EC 2.7.1.40) was studied using [U‐14C]glucose. It was concluded that in aleurone from maturing, rapidly acidifying grains the flux through the PEPC branch relative to that through PK is 3‐5 times greater than in young aleurone. This increase in flux can be accounted for by a 5‐fold increase in PEPC protein determined by western blotting and in PEPC activity measured in vitro.
Differential growth dependency of normal and habituated sugarbeet cell lines upon endogenous ethylene production and exogenous ethylene application
Authors: Bisbis Badia , Kevers Claire , Crèche Joel , Rideau Marc , Gaspar Thomas
Published: March 2003

A fully habituated (auxin‐ and cytokinin‐independent) nonorganogenic (HNO) sugarbeet (Beta vulgaris) callus produces very little ethylene as compared with a normal (N) hormone‐requiring callus of the same strain. Both callus types react by growth changes to application of inhibitors of ethylene biosynthesis and ethylene action, of 1‐aminocyclopropane‐1‐carboxylic acid (ACC) as the immediate precursor of ethylene, to transfer from light to darkness, and also to application of exogenous ethylene or an ethylene trapper. This indicates their growth dependency upon their endogenously biosynthesized ethylene and also their sensitivity to exogenous gas. However, the sensitivity was generally higher for the HNO callus producing naturally less ethylene. The weaker reaction of the HNO callus to the exogenous ethylene was attributed to its hyperhydric status (a water layer surrounding the cells). Because low ethylene production appears as a general characteristic of habituated cell lines, the causal and/or consequential relationships of this low ethylene production with other characteristics of habituated tissues (absence of exogenous hormones in the culture media, deficiency of cell differentiation, accumulation of polyamines in neoplastic tissues) are discussed.
ACC oxidase from Carica papaya: Isolation and characterization
Authors: Dunkley Hope M. , Golden Kerith D.
Published: March 2003

Most of the studies done on 1‐aminocyclopropane 1‐carboxylic acid (ACC) oxidase were done in vivo. It is only recently that in vitro studies have been carried out successfully on the enzyme. Here we report on in vitro studies of the enzyme that was isolated from Carica papaya. The enzyme had a Km of 37 µM and was inhibited by n‐propyl gallate (0.240 mM), sodium dithionite (0.022 mM), sodium metabisulphite (0.021 mM) and cobalt sulphate (0.100 mM). The activity of the enzyme increased with ripening, the enzyme was somewhat labile and activity was lost after 4 days at 14°C; activity was prolonged when the crude homogenate was kept at −15°C. Isolation and purification were achieved with ammonium sulphate precipitation followed by gel‐filtration (Sephadex G 100‐120) and ion‐exchange chromatography (DEAE‐Sephadex). Gel electrophoresis of the purified enzyme gave a single band which corresponded to a molecular mass of 27.5 kDa. The amino acid content of the enzyme showed a relatively high percentage of valine (10.4%). Enzyme activity was enhanced when dithiothreitol (3 mM) and bicarbonate ion (30 mM) were added to the assay medium. The production of ethylene from Carica papaya did not require pretreatment of the fruit with ethylene.
Gibberellin substitution for long day secondary induction of flowering in Poa pratensis
Authors: Heide O. M. , Blundell C. , King R. W. , Evans L. T.
Published: March 2003

Plants of Poa pratensis cv. Holt initiate inflorescence primordia when exposed to short days (SD) and low temperature, but require a secondary induction by at least 4 long days (LD) for further inflorescence development and stem elongation. Single or double applications of 10 µg per plant of gibberellins A1, A3, A5 and 16,17‐dihydro A5 (DHGA5) induced inflorescence development in a high proportion of plants in SD, but only if the plants were detillered to a single stem. Exposure to 2 LD cycles did not cause heading and flowering alone but enhanced the effect of exogenous gibberellins (GAs), bringing flowering to 100%. GA5 and DHGA5 were less effective than GA1 and GA3 in SD, especially with double applications, but were more effective than GA1 and GA3 when given together with 2 LD. The GAs had differential effects on vegetative growth and flowering, GA5 and DHGA5 causing much less leaf and stem growth than the other two GAs. Marginal induction, whether by LD or GA application, resulted in a high proportion of spikelets with viviparous proliferation. Thus, whereas GAs are inhibitory to the primary induction by SD, they can replace secondary induction by LD when vegetative growth is limited.