bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ileal Lymphonular Hyperplasia Is Not Associated With NOD2/CARD15 Mutations
Authors: Shaoul Ron , Eliakim Rami , Tamir Ada , Karban Amir 
Published: July 2006

ABSTRACTIntroduction:Lymphonodular hyperplasia (LNH) is a mass of lymphoid tissue that has been described in the terminal ileum, colon and duodenum mainly in children. Controversy exists regarding the benign nature of LNH. The combination of chronic abdominal pain and hematochezia leads many of these patients to undergo investigations for inflammatory bowel diseases. NOD2/CARD15 on chromosome 16 has been identified as a susceptibility gene for Crohn disease (CD). No study has yet examined the possible association of NOD2/CARD15 mutations with patients with LNH. The purpose of this study was to investigate the presence of NOD2/CARD15 mutations in patients with clinically proven LNH.Methods:Children and young adults with gastrointestinal symptoms diagnosed as having terminal ileum LNH were eligible for the study.Results:The study group consisted of 32 patients (15 males and 17 females), age range 3‐23 years, mean 13.1 ± 5 years. Twenty‐seven (84%) had abdominal pain, 3 (9%) had rectal bleeding. The duration of symptoms ranged from 1‐60 months (17.9 ± 14.5). Only 2 patients (6.2%) were found to be heterozygote for the NOD2/CARD15 mutation (1007 fs), whereas all of the others did not carry any of the 3 common mutant alleles. This number is significantly lower (P < 0.001) than the mutation prevalence demonstrated in both pediatric and adult Israeli CD patients.Conclusions:NOD2/CARD15 mutations are not associated with LNH. This may strengthen the lack of association between CD and LNH that has been previously reported. We suggest that genotyping NOD2/CARD15 may help to distinguish LNH from inflammatory bowel diseases in selected patients.
Plasma Zinc and Growth Status in Preadolescent Children with Cystic Fibrosis
Authors: Maqbool Asim , Schall Joan I. , Zemel Babette S. , Garcia‐Espana J. Felipe , Stallings Virginia A. 
Published: July 2006

ABSTRACTObjective:To investigate plasma zinc status in relation to dietary and supplemental zinc intake, growth and pulmonary status in preadolescent children with cystic fibrosis (CF) and pancreatic insufficiency (PI).Methods:Fasting plasma zinc was assessed in children (age, 8‐11 years) with CF and PI. Food (7‐day weighed records) and supplemental zinc intake, serum alkaline phosphatase and albumin, pulmonary function (spirometry), coefficient of fat absorption (%COA, 72‐hour fecal fat) and growth status [height adjusted for genetic potential (AHAZ), weight (WAZ) and BMI Z scores (BMIZ)] were assessed.Results:For the 62 children (32 males), mean plasma zinc (±SD) was 16.8 ± 3.1 μmol/L (110 ± 20 ug/dL). Sixty‐five percent of the subjects had levels above the study reference range of 9.2 to 15.3 μmol/L (60‐100 ug/dL); no subjects had low zinc levels. Median (range) total daily zinc intake was 279% (83‐988%) recommended dietary allowance, growth status was suboptimal (mean ± SD: AHAZ, −0.8 ± 1.0; WAZ, −0.5 ± 1.2; BMIZ, −0.2 ± 1.1), and forced expiratory volume at 1 second (FEV1) was 92 ± 13% predicted. Plasma zinc was not correlated with growth, pulmonary or alkaline phosphatase status. Plasma zinc was correlated with serum albumin (r = 0.25, P < 0.05) and was inversely correlated with coefficient of fat absorption (as %; r = −0.30, P = 0.02).Conclusions:Under current patterns of care in CF Centers, total zinc intake and plasma zinc status were adequate. These findings suggest that zinc was not a limiting micronutrient for preadolescent children with CF and PI and mild‐to‐moderate lung disease, and not likely contributing to their suboptimal growth status.
Characteristics of Persistent Diarrhea in a Community‐Based Cohort of Young US Children
Authors: Vernacchio Louis , Vezina Richard M. , Mitchell Allen A. , Lesko Samuel M. , Plaut Andrew G. , Acheson David W.K. 
Published: July 2006

ABSTRACTObjective:The objective of the study was to define the characteristics and microbiology of persistent diarrhea (PD) in US children.Methods:Six‐month prospective cohort study of a convenience sample of 604 healthy 6‐ to 36‐month‐old children recruited by the Slone Center Office‐based Research Network.Results:Of 611 diarrhea episodes, 50 (8.2%) lasted ≤ 14 days. The incidence of PD was 0.18 episodes per person‐year, and the median duration of episodes was 22.0 days (range, 14‐64 days). PD episodes were more likely than acute episodes to result in a medical visit (28.0% vs 8.2%; P = 0.0001). The most commonly used treatments were oral rehydration solution (12.0% of episodes) and antibiotics (6.0%). No bacterial or parasitic pathogens were associated with PD; but norovirus, rotavirus and sapovirus were each significantly more prevalent in PD stools compared with baseline stools, with relative risks of 12.4, 6.9 and 6.2, respectively. Fifty‐nine per cent of the PD specimens tested were negative for all studied pathogens.Conclusions:PD occurs with a frequency of approximately 1 case per 5 person‐years in US infants and young children. It seems to be a generally benign illness, with only 28% of cases presenting to medical care. Although viral pathogens seem to cause a minority of PD episodes in this population, most are not due to currently known infectious agents.
Osteoporosis in Pediatric Patients Suffering From Chronic Inflammatory Bowel Disease With and Without Steroid Treatment
Authors: Walther Frank , Fusch Christoph , Radke Michael , Beckert Sybille , Findeisen Annette 
Published: July 2006

ABSTRACTBackground:Children and adolescents suffering from inflammatory bowel disease (IBD) are at risk of developing osteoporosis as a result of treatment with corticosteroids as well as of nonsteroidal factors like inflammation and malnutrition. To study the impact of these factors on development of osteopathy, we compared the rate of osteoporosis in steroid‐naive and steroid‐treated pediatric IBD patients.Methods:In 90 patients (50 girls) with IBD (34 steroid‐naive, 53 steroid‐treated, 3 not known) aged 8.8 to 19.2 (14.4 ± 2.2) years and 52 controls (27 girls) aged 6.1 to 17.6 (12.9 ± 3.0) years, bone mineral density (BMD) of the lumbar spine was assessed with dual energy x‐ray absorptiometry. Areal BMD values were transformed into volumetric densities called bone mineral apparent density (BMAD) and expressed as standard deviation scores (SDS) on the basis of the BMAD values of the controls.Results:The rate of osteoporotic patients (BMAD‐SDS < −2) was 8% in girls and 20% in boys. There was a similar proportion of osteoporosis in steroid‐naive (12%) and steroid‐treated (11%) patients. SDS of body height showed a significant positive correlation with BMD‐SDS but not with BMAD‐SDS in almost all patient subgroups, indicating an interfering dependency of BMD from bone size.Conclusions:The prevalence of osteoporosis in pediatric patients with IBD is approximately the same as in adult patients. Osteoporosis is already present before steroid treatment. Data of dual energy x‐ray absorptiometry measurements should be transformed into volumetric parameters to compensate for short stature. Otherwise, a lot of growth‐stunted patients may be falsely diagnosed as osteopenic.
Cold-Active Winter Rye Glucanases with Ice-Binding Capacity
Authors: Yaish Mahmoud W.F. , Doxey Andrew C. , McConkey Brendan J. , Moffatt Barbara A. , Griffith Marilyn 
Published: July 2006

Abstract
Extracellular pathogenesis-related proteins, including glucanases, are expressed at cold temperatures in winter rye (Secale cereale) and display antifreeze activity. We have characterized recombinant cold-induced glucanases from winter rye to further examine their roles and contributions to cold tolerance. Both basic β-1,3-glucanases and an acidic β-1,3;1,4-glucanase were expressed in Escherichia coli, purified, and assayed for their hydrolytic and antifreeze activities in vitro. All were found to be cold active and to retain partial hydrolytic activity at subzero temperatures (e.g. 14%–35% at −4°C). The two types of glucanases had antifreeze activity as measured by their ability to modify the growth of ice crystals. Structural models for the winter rye β-1,3-glucanases were developed on which putative ice-binding surfaces (IBSs) were identified. Residues on the putative IBSs were charge conserved for each of the expressed glucanases, with the exception of one β-1,3-glucanase recovered from nonacclimated winter rye in which a charged amino acid was present on the putative IBS. This protein also had a reduced antifreeze activity relative to the other expressed glucanases. These results support the hypothesis that winter rye glucanases have evolved to inhibit the formation of large, potentially fatal ice crystals, in addition to having enzymatic activity with a potential role in resisting infection by psychrophilic pathogens. Glucanases of winter rye provide an interesting example of protein evolution and adaptation aimed to combat cold and freezing conditions.
Rapid, Futile K+ Cycling and Pool-Size Dynamics Define Low-Affinity Potassium Transport in Barley
Authors: Szczerba Mark W. , Britto Dev T. , Kronzucker Herbert J. 
Published: July 2006

Abstract
Using the short-lived radiotracer 42K+, we present a comprehensive subcellular flux analysis of low-affinity K+ transport in plants. We overturn the paradigm of cytosolic K+ pool-size homeostasis and demonstrate that low-affinity K+ transport is characterized by futile cycling of K+ at the plasma membrane. Using two methods of compartmental analysis in intact seedlings of barley (Hordeum vulgare L. cv Klondike), we present data for steady-state unidirectional influx, efflux, net flux, cytosolic pool size, and exchange kinetics, and show that, with increasing external [K+] ([K+]ext), both influx and efflux increase dramatically, and that the ratio of efflux to influx exceeds 70% at [K+]ext ≥ 20 mm. Increasing [K+]ext, furthermore, leads to a shortening of the half-time for cytosolic K+ exchange, to values 2 to 3 times lower than are characteristic of high-affinity transport. Cytosolic K+ concentrations are shown to vary between 40 and 200 mm, depending on [K+]ext, on nitrogen treatment (NO3− or NH4+), and on the dominant mode of transport (high- or low-affinity transport), illustrating the dynamic nature of the cytosolic K+ pool, rather than its homeostatic maintenance. Based on measurements of trans-plasma membrane electrical potential, estimates of cytosolic K+ pool size, and the magnitude of unidirectional K+ fluxes, we describe efflux as the most energetically demanding of the cellular K+ fluxes that constitute low-affinity transport.
Induction of Differentiation in the Shoot Apical Meristem by Transient Overexpression of a Retinoblastoma-Related Protein
Authors: Wyrzykowska Joanna , Schorderet Martine , Pien Stéphane , Gruissem Wilhelm , Fleming Andrew J. 
Published: July 2006

Abstract
The shoot apical meristem contains cells that undergo continual growth and division to generate the building blocks for the aerial portion of the plant. As cells leave the meristem, they undergo differentiation to form specific cell types. Most notably, heterotrophic cells of the meristem rapidly gain autotrophic capability by synthesis and assembly of components of the chloroplast. At the same time, cells undergo enlargement via vacuolation. Despite significant advances in the characterization of transcriptional networks involved in meristem maintenance and leaf determination, our understanding of the actual mechanism of meristem cell differentiation remains very limited. Using a microinduction technique, we show that local, transient overexpression of a retinoblastoma-related (RBR) protein in the shoot apical meristem is sufficient to trigger cells in the meristem to undergo the initial stages of differentiation. Taken together with recent data showing that RBR protein plays a key role in restricting stem cell differentiation in the root apical meristem, our data contribute to an emerging picture of RBR proteins as a central part of the mechanism controlling meristem cell differentiation.
The hpa1 Mutant of Arabidopsis Reveals a Crucial Role of Histidine Homeostasis in Root Meristem Maintenance
Authors: Mo Xiaorong , Zhu Qingyu , Li Xiang , Li Jing , Zeng Qingning , Rong Honglin , Zhang Hanma , Wu Ping 
Published: July 2006

Abstract
Histidine (His) is an essential ingredient for protein synthesis and is required by all living organisms. In higher plants, although there is considerable evidence that His is essential for plant growth and survival, there is very little information as to whether it plays any specific role in plant development. Here, we present evidence for such a role of this amino acid in root development in Arabidopsis (Arabidopsis thaliana) from the characterization of a novel Arabidopsis mutant, hpa1, which has a very short root system and carries a mutation in one of the two Arabidopsis histidinol-phosphate aminotransferase (HPA) genes, AtHPA1. We have established that AtHPA1 encodes a functional HPA and that its complete knockout is embryo lethal. Biochemical analysis shows that the mutation in hpa1 only resulted in a 30% reduction in free His content and had no significant impact on the total His content. It did not cause any known symptoms of His starvation. However, the mutant displayed a specific developmental defect in root meristem maintenance and was unable to sustain primary root growth 2 d after germination. We have demonstrated that the root meristem failure in the mutant is tightly linked to the reduction in free His content and could be rescued by either exogenous His supplementation or AtHPA1 overexpression. Our results therefore reveal an important role of His homeostasis in plant development.
Efficient Virus-Induced Gene Silencing in Arabidopsis
Authors: Burch-Smith Tessa M. , Schiff Michael , Liu Yule , Dinesh-Kumar S.P. 
Published: July 2006

AbstractVirus-induced gene silencing (VIGS) is a plant RNA-silencing technique that uses viral vectors carrying a fragment of a gene of interest to generate double-stranded RNA, which initiates the silencing of the target gene. Several viral vectors have been developed for VIGS and they have been successfully used in reverse genetics studies of a variety of processes occurring in plants. This approach has not been widely adopted for the model dicotyledonous species Arabidopsis (Arabidopsis thaliana), possibly because, until now, there has been no easy protocol for effective VIGS in this species. Here, we show that a widely used tobacco rattle virus-based VIGS vector can be used for silencing genes in Arabidopsis ecotype Columbia-0. The protocol involves agroinfiltration of VIGS vectors carrying fragments of genes of interest into seedlings at the two- to three-leaf stage and requires minimal modification of existing protocols for VIGS with tobacco rattle virus vectors in other species like Nicotiana benthamiana and tomato (Lycopersicon esculentum). The method described here gives efficient silencing in Arabidopsis ecotype Columbia-0. We show that VIGS can be used to silence genes involved in general metabolism and defense and it is also effective at knocking down expression of highly expressed transgenes. A marker system to monitor the progress and efficiency of VIGS is also described.
A Variable Cluster of Ethylene Response Factor–Like Genes Regulates Metabolic and Developmental Acclimation Responses to Submergence in Rice
Authors: Fukao Takeshi , Xu Kenong , Ronald Pamela C. , Bailey-Serres Julia 
Published: July 2006

Abstract
Submergence-1 (Sub1), a major quantitative trait locus affecting tolerance to complete submergence in lowland rice (Oryza sativa), contains two or three ethylene response factor (ERF)–like genes whose transcripts are regulated by submergence. In the submergence-intolerant japonica cultivar M202, this locus encodes two ERF genes, Sub1B and Sub1C. In the tolerant near-isogenic line containing the Sub1 locus from the indica FR13A, M202(Sub1), the locus additionally encodes the ERF gene Sub1A. During submergence, the tolerant M202(Sub1) displayed restrained leaf and internode elongation, chlorophyll degradation, and carbohydrate consumption, whereas the enzymatic activities of pyruvate decarboxylase and alcohol dehydrogenase were increased significantly compared with the intolerant M202. Transcript levels of genes associated with carbohydrate consumption, ethanolic fermentation, and cell expansion were distinctly regulated in the two lines. Sub1A and Sub1C transcript levels were shown to be upregulated by submergence and ethylene, with the Sub1C allele in M202 also upregulated by treatment with gibberellic acid (GA). These findings demonstrate that the Sub1 region haplotype determines ethylene- and GA-mediated metabolic and developmental responses to submergence through differential expression of Sub1A and Sub1C. Submergence tolerance in lowland rice is conferred by a specific allele variant of Sub1A that dampens ethylene production and GA responsiveness, causing quiescence in growth that correlates with the capacity for regrowth upon desubmergence.
Premières observations de Verticillium dahliae sur olivier en Tunisie
Authors: Triki M. A. , Hassaïri A. , Mahjoub M. 
Published: July 2006

Au cours des prospections effectuées dans les oliveraies de la délégation de Mahres (région de Sfax) située au centre‐est de la Tunisie, 12 cas de dépérissement d’oliviers âgés, du cv. ‘Chemlali’ ont été observés dans deux parcelles voisines. Dans ces deux vergers, les oliviers malades sont répartis en foyers. Les investigations au champ et au laboratoire ont permis de mettre en évidence la présence du champignon Verticillium dahliae, qui est ainsi signalé pour la première fois en Tunisie sur olivier.
IFN‐γ and Delayed‐Type Hypersensitivity are Associated with Cutaneous Leishmaniasis in Vervet Monkeys following Secondary Rechallenge with Leishmania major
Authors: OLOBO J. O. , REID G. D. F. , GITHURE J. I. , ANJILI C. O. 
Published: July 2006

IFN‐γ levels and delayed‐type hypersensitivity (DIM) responses were evaluated in vervet monkeys, following secondary infection with leishmania major (L. major). The animals had previously been vaccinated with leishmanial antigen, exposed to a primary infection and allowed to self‐cure. Supernatants of peripheral blood mononuclear cell (PBMC) cultures, stimulated with either L. major antigen or Concanavalin A (Con A), were examined for the presence of IFN‐γ in a double sandwich enzyme‐linked immunosorbent ASSAY (ELISA). Significant levels of IFN‐γ were detected during active disease and following Self‐cure in both antigen and Con A supernatants Higher levels of IFN‐y were, however, present during active disease as compared with after self‐cure. Positive and strong DTH responses were elicited in all experimental animals, following intradermal injection of fixed promastigotes (5×107/animal) before rechallenge, during active infection and following self‐cure. Again, strongest DTH responses were obtained during active infection as compared with the other sampling pointThere was a correlation between IFN‐γ levels and DTH responses. It was concluded that IFN‐γ secretion and positive DTH responses are associated with secondary L. major infection and represent specific immunological correlates of protection in this disease model.
Anaplasmosis in Uganda. I. Use of Dried Blood on Filter Paper and Serum Samples for Serodiagnosis of Anaplasmosis—a Comparative Study
Authors: SSENYONGA G. S. Z. , MONTENEGRO‐JAMES S. , KAKOMA I. , HANSEN R. 
Published: July 2006

The suitability of blood collected on filter papers in comparison with corresponding conventional serum samples in the diagnosis of bovine anaplasmosis was studied using the Complement Fixation Test (CFT), DOT‐ELISA, Western immunoblot and Rapid Card Agglutination Test (RCAT). Dried blood on Whatman filter paper no. I was eluted in 1.8 ml of PBS 0.05% Tween 20 given an initial dilution of 1:100.The reactivity in both DOT‐ELISA and Western immunoblotting was similar to that obtained with the sera diluted 1:100. Filter paper samples gave lower reactivity in all the tests as compared with corresponding serum samples. There was no significant difference in the reactivity between the eluates from filter papers stored at room temperature and those stored at 4°C. Storage at room temperature did not significantly affect reactivity for up to 6 months. Eluates from filter papers stored for 6 months at room temperature continued to give similar reactivity to those from freshly prepared filter papers in both DOT‐ELISA and Western blot, and in the Rapid Card Agglutination Test.It is concluded that collecting blood on filter papers is a suitable technique for large‐scale screening and for seroepidemiological studies on anaplasmosis, and offers many advantages especially in developing countries where transport and cold chain facilities are a major constraint.
Anti‐Sperm and Anti‐Ovum Vaccines: the Selection of Candidate Antigens and the Outcome of Preclinical Studies
Authors: ISAHAKIA M. A. , BAMBRA C. S. 
Published: July 2006

A clear conceptual basis for anti‐sperm and other modes of immunological birth control exists in spite of the limited basic research done on surface antigens of sperm or egg. In the normal physiological condition, the immune system does not respond to sperm, egg or fetus. Compared with anti‐egg or anti‐fetus immunocontraception, an anti‐sperm vaccine has two theoretical advantages. First it would work in both males and females; second, it would not raise problems of autoimmunity in the female if a sperm‐specific protein is used.However, for the development of such contraceptive vaccines the following scientific questions need to be resolved: (1) what surface protein to use as an antigen: (2) what adjuvant to use in humans for an anti‐fertility vaccine: (3) how to maintain a high titre; (4) how the contraceptive effect will be terminated; and (5) what are the potential side‐effects.
Anti‐LHRH and Anti‐Pituitary Gonadotropin Vaccines: their Development and Clinical Applications
Authors: THAU R. 
Published: July 2006

Active immunization against hormones involved in the regulation of reproduction is a promising approach to immunocontraception. The hypothalamic peptide, LHRH, controls the synthesis and release of the pituitary gonadotropins, LH and FSH, which regulate gonadal steroidogenesis, sperm production, follicular development and ovulation. Immunizing female primates against LHRH or LH induces infertility, but also disrupts the menstrual cycle. Immunization against the β subunit of the placental hormone, chorionic gonadotropin (hCG), or its fragment prevents pregnancy without interfering with menstrual cycles or ovulation. hCG vaccines have reached the stage of clinical trials.FSH and LHRH have been tested for immunocontraception in male primates. While active as well as passive immunization against FSH reduced spermatogenesis severely, azoospermia could not be achieved consistently. Immunization against LHRH effectively suppressed spermatogenesis in rats and rabbits. Normal sexual behaviour was maintained by concomitant androgen administration. Fertility was restored when antibody titres declined and no adverse effects were observed. A number of LHRH vaccine preparations are being tested in men in several countries, including the United States. Since the LHRH vaccine reduces serum testosterone levels the first clinical studies involve men with prostate cancer. These trials will be followed by immunization of normal men if the antibody response is sufficient and no adverse effects are observed.