bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel phosphorylation of histone H3 at threonine 11 that temporally correlates with condensation of mitotic and meiotic chromosomes in plant cells
Authors: Houben A. , Demidov D. , Rutten T. , Scheidtmann K.H.
Published: March 2005

A novel mitosis-specific phosphorylation site in histone H3 at threonine 11 has been described for mammalian cells. This modification is restricted to the centromeric region while phosphorylation at the classical H3 sites, Ser10 and Ser28 occurs along the entire chromosomal arms. Using phosphorylation state-specific antibodies we found that phosphorylation at threonine 11 occurs also in plant cells, during mitosis as well as meiosis. However, in contrast to animal cells, ph(Thr11)H3 was distributed along the entire length of condensed chromosomes, whereas H3 phosphorylated at Ser10 and Ser28 appeared to be restricted to centromeric/pericentromeric chromatin. Phosphorylation at Thr11 started in prophase and ended in telophase, it correlated with the condensation of mitotic and meiotic chromosomes and was independent of the distribution of late replicating heterochromatin and Giemsa-banding positive regions. Interestingly, treatment of cells with the phosphatase inhibitor cantharidin revealed a high level of Thr11 phosphorylation in interphase cells, in this case particularly in pericentromeric regions. These data show that histone modifications are highly dynamic. Moreover, animal and plant organisms may have evolved individual histone codes.
Minichromosomes derived from the B chromosome of maize
Authors: Kato A. , Zheng Y.-Z. , Auger D.L. , Phelps-Durr T. , Bauer M.J. , Lamb J.C. , Birchler J.A.
Published: March 2005

Fourteen minichromosomes derived from the B chromosome of maize are described. The centromeric region of the B chromosome contains a specific repetitive DNA element called the B repeat. This sequence was used to determine the transmission frequency of the different types of minichromosomes over several generations via Southern blot analysis at each generation. In general, the minichromosomes have transmission rates below the theoretical 50% frequency of a univalent chromosome. The gross structure of each minichromosome was determined using fluorescence in situ hybridization (FISH) on root tip chromosome spreads. The presence of the B centromeric repeat and of the adjacent heterochromatic knob sequences was determined for each minichromosome. In two cases, the amount of the centromeric knob repeat is increased relative to the progenitor chromosome. Other isolates have reduced or undetectable levels of the knob sequence. Potential uses of the minichromosomes are discussed.
Chromosome organization in wheat endosperm and embryo
Authors: Wegel E. , Shaw P.J.
Published: March 2005

We have analysed the chromosome organization in endosperm and embryo of bread wheat (Triticum aestivum L.), in order to compare these tissues with developing anthers, in which the centromeres associate, and the developing root xylem vessel cells, in which the chromosomes endoreduplicate to become polytene and associate via their centromeres. Both endosperm and embryo showed a typical Rabl configuration and a degree of non-homologous centromere association and the endosperm also showed extensive telomere association. Wheat endosperm is initially triploid and during its development a percentage of the nuclei increase their DNA content to 6C and 12C. 6C nuclei showed twice as many centromeres as 3C nuclei and the centromere number increased further in 12C nuclei. The higher the C-content of a nucleus the more the telomeres associated in endosperm. The vast majority of 12C nuclei showed six rye chromosome arms, although a few showed three associated groups of rye chromosome arms. This means that during endosperm development wheat nuclei show both polyploidization and polytenization.
A strategy to investigate the plant meiotic proteome
Authors: Sánchez-Morán E. , Mercier R. , Higgins J.D. , Armstrong S.J. , Jones G.H. , Franklin F.C.H.
Published: March 2005

The analysis of meiosis in higher plants has benefited considerably in recent years from the completion of the genome sequence of the model plant Arabidopsis thaliana and the development of cytological techniques for this species. A combination of forward and reverse genetics has provided important routes toward the identification of meiotic genes in Arabidopsis. Nevertheless identification of certain meiotic genes remains a challenge due to problems such as limited sequence conservation between species, existence of closely related gene families and in some cases functional redundancy between gene family members. Hence there is a requirement to develop new experimental approaches that can be used in conjunction with existing methods to enable a greater range of plant meiotic genes to be identified. As one potential route towards this goal we have initiated a proteomics-based approach. Unfortunately, the small size of Arabidopsis anthers makes an analysis in this species technically very difficult. Therefore we have initially focussed on Brassica oleracea which is closely related to Arabidopsis, but has the advantage of possessing significantly larger anthers. The basic strategy has been to use peptide mass-finger printing and matrix-assisted laser desorption ionization time of flight mass spectrometry to analyse proteins expressed in meiocytes during prophase I of meiosis. Initial experiments based on the analysis of proteins from staged anther tissue proved disappointing due to the low level of detection of proteins associated with meiosis. However, by extruding meiocytes in early prophase I from individual anthers prior to analysis a significant enrichment of meiotic proteins has been achieved. Analysis suggests that at least 18% of the proteins identified by this route have a putative meiotic function and that this figure could be as high as one-third of the total. Approaches to increase the enrichment of proteins involved in meiotic recombination and chromosome synapsis are also described.
Strategies for the study of meiosis in rye
Authors: Jenkins G. , Mikhailova E.I. , Langdon T. , Tikholiz O.A. , Sosnikhina S.P. , Jones R.N.
Published: March 2005

We describe how we are furthering our understanding of meiosis in rye (Secale cereale L.) using a combination of cytogenetic and molecular biological approaches. Fluorescent in situ hybridisation, electron microscopy of synaptonemal complexes, sequencing of meiosis-specific genes, and the immunolocalisation of recombinogenic proteins are being combined to build up phenotypic “identikits” of wild type, asynaptic mutants sy1 and sy9, and desynaptic mutant sy10. From this information, we review the status of our current understanding of the genetic control of meiosis in rye, and consider strategies for determining more precisely the interrelationships between meiosis-specific genes and their products.
Centromere-specific repetitive sequences from Torenia, a model plant for interspecific fertilization, and whole-mount FISH of its interspecific hybrid embryos
Authors: Kikuchi S. , Kishii M. , Shimizu M. , Tsujimoto H.
Published: March 2005

Torenia fournieri is a good model plant to study fertilization in plants because it is easy to observe the fertilization process due to the protruding nature of the embryo sac. To study the location and movement of chromosomes and their centromeres in early embryogenesis of interspecific hybrid plants, we isolated two families of centromere-specific tandem repetitive sequences from T. fournieri and T. bailonii, and named them the “TCEN-family” and “BCEN-family”, respectively. Both sequences consisted of a repeat unit of 52 bp located in the pericentric and centric heterochromatins. All signals of both sequences were prominent, but their intensity varied among the chromosomes. DNA-blot hybridization indicated the presence of similar sequences of TCEN-family in T. concolor, N. caerulea, and “Summer Wave”, whereas the BCEN-family was found only in T. bailonii, thus indicating the wide or specific distribution of their repetitive families observed. We also applied whole-mount FISH to the interspecific hybrid embryos by using TCEN- and BCEN-family sequences as probes. Our results suggest that whole-mount FISH with the species-specific centromere sequences as probes is an ideal method to analyze the dynamics of chromosomes and centromeres in interspecific fertilization and early embryogenesis.
Allopolyploidy – a shaping force in the evolution of wheat genomes
Authors: Feldman M. , Levy A.A.
Published: March 2005

Recent studies have shown that allopolyploidy accelerates genome evolution in wheat in two ways: (1) allopolyploidization triggers rapid genome changes (revolutionary changes) through the instantaneous generation of a variety of cardinal genetic and epigenetic alterations, and (2) the allopolyploid condition facilitates sporadic genomic changes during the life of the species (evolutionary changes) that are not attainable at the diploid level. The revolutionary changes comprise (1) non-random elimination of coding and non-coding DNA sequences, (2) epigenetic changes such as DNA methylation of coding and non-coding DNA leading, among others, to gene silencing, (3) activation of genes and retroelements which in turn alters the expression of adjacent genes. These highly reproducible changes occur in the F1 hybrids or in the first generation(s) of the nascent allopolyploids and were similar to those that occurred twice in nature: first in the formation of allotetraploid wheat (∼0.5 million years ago) and second in the formation of hexaploid wheat (∼10,000 years ago). Elimination of non-coding sequences from one of the two homoeologous pairs in tetraploids and from two homoeologous pairs in hexaploids, augments the differentiation of homoeologous chromosomes at the polyploid level, thus providing the physical basis for the diploid-like meiotic behavior of allopolyploid wheat. Regulation of gene expression may lead to improved inter-genomic interactions. Gene inactivation brings about rapid diploidization while activation of genes through demethylation or through transcriptional activation of retroelements altering the expression of adjacent genes, leads to novel expression patterns. The evolutionary changes comprise (1) horizontal inter-genomic transfer of chromosome segments between the constituent genomes, (2) production of recombinant genomes through hybridization and introgression between different allopolyploid species or, more seldom, between allopolyploids and diploids, and (3) mutations. These phenomena, emphasizing the plasticity of the genome with regards to both structure and function, might improve the adaptability of the newly formed allopolyploids and facilitate their rapid and successful establishment in nature.
Production of alien chromosome additions and their utility in plant genetics
Authors: Chang S.-B. , de Jong H.
Published: March 2005

Breeding programs aiming at transferring desirable genes from one species to another through interspecific hybridization and backcrossings often produce monosomic and disomic additions as intermediate crossing products. Such aneuploids contain alien chromosomes added to the complements of the recipient parent and can be used for further introgression programs, but lack of homoeologous recombination and inevitable segregation of the alien chromosome at meiosis make them often less ideal for producing stable introgression lines. Monosomic and disomic additions can have specific morphological characteristics, but more often they need additional confirmation of molecular marker analyses and assessment by fluorescence in situ hybridization with genomic and chromosome-specific DNA as probes. Their specific genetic and cytogenetic properties make them powerful tools for fundamental research elucidating regulation of homoeologous recombination, distribution of chromosome-specific markers and repetitive DNA sequences, and regulation of heterologous gene expression. In this overview we present the major characteristics of such interspecific aneuploids highlighting their advantages and drawbacks for breeding and fundamental research.
Detection of alien chromatin introgression from Thinopyrum into wheat using S genomic DNA as a probe – A landmark approach for Thinopyrum genome research
Authors: Chen Q.
Published: March 2005

The introduction of alien genetic variation from the genus Thinopyrum through chromosome engineering into wheat is a valuable and proven technique for wheat improvement. A number of economically important traits have been transferred into wheat as single genes, chromosome arms or entire chromosomes. Successful transfers can be greatly assisted by the precise identification of alien chromatin in the recipient progenies. Chromosome identification and characterization are useful for genetic manipulation and transfer in wheat breeding following chromosome engineering. Genomic in situ hybridization (GISH) using an S genomic DNA probe from the diploid species Pseudoroegneria has proven to be a powerful diagnostic cytogenetic tool for monitoring the transfer of many promising agronomic traits from Thinopyrum. This specific S genomic probe not only allows the direct determination of the chromosome composition in wheat-Thinopyrum hybrids, but also can separate the Th. intermedium chromosomes into the J, JS and S genomes. The JS genome, which consists of a modified J genome chromosome distinguished by S genomic sequences of Pseudoroegneria near the centromere and telomere, carries many disease and mite resistance genes. Utilization of this S genomic probe leads to a better understanding of genomic affinities between Thinopyrum and wheat, and provides a molecular cytogenetic marker for monitoring the transfer of alien Thinopyrum agronomic traits into wheat recipient lines.
Development and characterization of potato-Solanum brevidens chromosomal addition/substitution lines
Authors: Dong F. , Tek A.L. , Frasca A.B.L. , McGrath J.M. , Wielgus S.M. , Helgeson J.P. , Jiang J.
Published: March 2005

Solanum brevidens is a wild diploid potato species possessing high levels of resistances to several major potato diseases. We previously developed fertile somatic hybrids between S. brevidens and the cultivated potato (Solanum tuberosum) in order to introgress disease resistances from this wild species into potato. A series of backcross progenies was developed from a hexaploid somatic hybrid A206. Using a combination of S. brevidens-specific randomly amplified polymorphic DNA (RAPD) markers and a sequential genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH) technique, we identified all 12 S. brevidens chromosomes in the backcross progenies. Seven potato-S. brevidens monosomic chromosome addition lines (chromosomes 1, 3, 4, 5, 8, 9 and 10) and one monosomic substitution line (chromosome 6) were identified, and the remaining four S. brevidens chromosomes (2, 7, 11, and 12) were included in two other lines. These chromosomal addition/substitution stocks provide valuable tools for potato cytogenetic research, and can be used to introgress disease resistances from S. brevidens into potato.
Cytogenetics of Triticum × Dasypyrum hybrids and derived lines
Authors: Minelli S. , Ceccarelli M. , Mariani M. , de Pace C. , Cionini P.G.
Published: March 2005

Genomic in situ hybridization was used to study Triticum × Dasypyrum wide hybrids and derived lines. A cytogenetic investigation was carried out in progenies of (i) amphiploids derived from T. turgidum var. durum (T. durum; 2n = 14; genomes AABB) × D. villosum (2n = 14; genome VV), (ii) three-parental hybrids (T. durum × D. villosum) × T. aestivum (2n = 42, genomes A′A′B′B′D′D′), and (iii) T. aestivum aneuploid lines carrying D. villosum chromosomes or chromatin. The amphiploids derived from T. durum × D. villosum showed a stable chromosomal constitution, made up of 14 V chromosomes, 14 chromosomes carrying the wheat A genome and 14 chromosomes carrying the B genome. High karyological instability was observed in the progenies of three-parental hybrids ([T. durum × D. villosum] × T. aestivum). Plants having the expected 14 A chromosomes, 14 B chromosomes, 7 D chromosomes, and 7 V chromosomes were rather rare (4.5%). Many progeny plants (45.5%) had the hexaploid wheat genome with 42 chromosomes and lacked any detectable D. villosum chromatin. Other plants (50%) had 14 A chromosomes and 14 B chromosomes, plus variable numbers of D and V chromosomes, the former being better retained than the latter in most cases. Some T. aestivum lines carrying D. villosum chromosomes or chromatin, as the result of addition, substitution, or recombination events or even a combination of these karyological events, were found to be stable. Other lines were unstable, and these lines carried 1V, 3V, or 5V chromosomes or their portions. Substitution or recombination events where 1V chromosomes were involved could concern the homeologous counterparts in both the A and B and D genomes of wheat. No line could be recovered where the shorter arm of 3V chromosomes was present. Changes in the morphology and banding pattern of V chromosomes were observed in hybrids that did not carry the entire D. villosum complement. By comparing the results of our cytogenetic analyses with certain phenotypic characteristics of the lines studied, genes for discrete traits could be assigned to specific V chromosomes or V chromosome arms. From the frequency of V chromosomes that were involved in chromatin exchanges with or substituted for one of their homeologous counterparts in the A, B, and D wheat genomes, it was inferred that D. villosum belongs to the same phyletic lineage as T. urartu (donor of the A genome of wheat) and Aegilops speltoides (B genome), and that Ae. squarrosa (D genome) diverged earlier from D. villosum.
Behavioural and Demographic Factors during Early Childhood and Poor Dental Health at 10 Years of Age
Authors: Mattila M.-L. , Rautava P. , Aromaa M. , Ojanlatva A. , Paunio P. , Hyssälä L. , Helenius H. , Sillanpää M.
Published: March 2005

The aim was to elucidate whether variables recorded in early childhood would have a long-lasting predictive value of poor dental health at the age of 10 years in a prospectively followed Finnish population-based cohort setting. The second aim was to find new tools for preventive work in order to improve dental health among children. Poor dental health (dmft + DMFT ≧ 5) at 10 years of age was associated with child’s nocturnal juice drinking at 18 months. It was associated with the following factors at age 3 years: frequent consumption of sweets; infrequent tooth brushing; plaque and caries on teeth. Of family factors, the following were significant: father’s young age at birth of the child; mother’s basic 9-year education; mother’s caries (i.e. several carious teeth per year), and father’s infrequent tooth brushing. Early childhood risk factors of poor dental health seem to be stable even after 10 years of life and the changing of teeth from primary to permanent ones. In preventive work, dental health care staff could offer support to those parents with risk factors in their child rearing tasks.
Influence of the Organic Matrix on Root Dentine Erosion by Citric Acid
Authors: Hara A.T. , Ando M. , Cury J.A. , Serra M.C. , González-Cabezas C. , Zero D.T.
Published: March 2005

This investigation was conducted in an attempt to clarify the role of the organic matrix in bovine dentine demineralisation by 1% citric acid. Dentine slabs (n = 15) were treated for 2 min with 10% sodium hypochlorite (NaOCl, a strong protein solvent), 2% glutaraldehyde (GDA, a protein fixative) or deionised water (DIW, as negative control) prior to each of 5 demineralisation periods of 30 min. The mineral loss (ΔZ), lesion depth (LD) and surface loss (SL) were determined after each period of demineralisation, by transverse microradiography. The NaOCl-treated group showed higher ΔZ and LD than the GDA- and DIW-treated groups. No differences between GDA and DIW groups were found. The ΔZ and LD profiles were explained by quadratic fits (r2 >0.80; p = 0.001) in all groups. SL was detected only in the NaOCl-treated group. The data suggested that the maintenance of the organic matrix in the lesion might be important to reduce the erosion progression rate.
Thickness Measurement of Worn Molar Cusps by Ultrasound
Authors: Arslantunali Tagtekin D. , Öztürk F. , Lagerweij M. , Hayran O. , Stookey G.K. , Çaliskan Yanikoglu F.
Published: March 2005

This study aimed to evaluate the effectiveness of an ultrasonic system for in vitro measurement of cusp tips of human teeth. Each worn cusp of 12 molar teeth was measured with an industrial ultrasonic system. The teeth were sectioned and measured by polarized light microscopy. The ultrasonic measurements and histological readings were moderately correlated (r = 0.601, p < 0.01). The ultrasonic system used in this study seemed a promising method for measuring thickness of worn cusp tips of extracted human molar teeth.
The Influence of the Calibration Mode of a Laser Fluorescence Device on Caries Detection
Authors: Braun A. , Krause F. , Jepsen S.
Published: March 2005

The aim of the present study was to assess the influence of the calibration mode of a laser fluorescence measurement device on caries detection. While positioning the probe on an occlusal carious lesion or stained fissure using a clamp, the occlusal surface of each of 62 teeth was covered with a light-body silicone impression material to facilitate a reproducible probe position. Then, measurements of the occlusal lesions were performed after standard and individual calibration at four non-carious areas on the buccal surface of each tooth. Mean laser fluorescence values of the occlusal reading point following standard calibration were about 4–5 units higher compared to values measured after individual calibration. After 1 week, readings after both standard and individual calibration were not different from baseline values (p > 0.05). During individual calibration, a mean range of about 2 units could be observed when comparing the readings of the occlusal reading point with respect to the four different areas of each buccal surface. The present study indicates that laser fluorescence readings are dependent on the mode of calibration. Moreover, for individual calibration, the probe position has to be recorded carefully. It is suggested that the same mode of calibration should always be used, when employing laser fluorescence measurements for longitudinal caries monitoring.
Pulmonary Hypertension in Men with Thyrotoxicosis
Authors: Soroush-Yari Ardeshir , Burstein Samuel , Hoo Guy W. Soo , Santiago Silverio M.
Published: March 2005

Thyrotoxicosis has a myriad of respiratory symptoms including dyspnea. Pulmonary hypertension may contribute to the respiratory symptoms of thyrotoxicosis, but is often unrecognized. We describe 3 male patients with thyrotoxicosis and associated pulmonary hypertension. Case reports of an additional 15 patients are also reviewed. In patients with thyrotoxicosis and pulmonary hypertension, treatment of thyrotoxicosis alone is associated with improvement in pulmonary hypertension. Previous reports have consisted of mostly female patients, but we report 3 men. When all cases are considered, the typical patient is female (10/14 = 71%), middle-aged (48 years), with mean pulmonary artery systolic pressures improving from 56 to 32 mm Hg with treatment. Autoantibodies were detected in 10/14 (71%) patients. The response to treatment (medical or surgical) of thyrotoxicosis supports the hypothesis that hyperthyroidism is either a cause of pulmonary hypertension, or a factor that may unmask pulmonary hypertension. Recognition is important since treatment and response are very different compared to other patients with pulmonary hypertension. This association may not be readily considered in men, since most reports have been of women.
Drug Safety in the Treatment of Crohn’s Disease
Authors: Juillerat Pascal , Felley Christian , Mottet Christian , Froehlich Florian , Vader John-Paul , Burnand Bernard , Gonvers Jean-Jacques , Michetti Pierre
Published: March 2005

The management of Crohn’s disease usually consists of a succession of short-term acute phase treatments followed by long-term maintenance therapy. The disease affects young patients and for this reason the long-term safety of the drugs needs to be especially taken into consideration. The safety, dose, duration for optimal efficacy and the most frequent adverse events will be described in this article.
Therapy of Mild to Moderate Luminal Crohn’s Disease
Authors: Michetti Pierre , Juillerat Pascal , Mottet Christian , Gonvers Jean-Jacques , Burnand Bernard , Vader John-Paul , Froehlich Florian , Felley Christian
Published: March 2005

The management of luminal Crohn’s disease, the most common form of initial presentation of the disease, depends on the location and the severity of the lesions. Mild to moderate disease represents a relatively large proportion of patients with a first flare of luminal disease, which may also be associated with perianal disease. As quality of life of these patients correlates with disease activity, adequate therapy is a central goal of the overall patient management. Treatment options include mainly sulfasalazine, budesonide and systemic steroids, while the role of mesalazine and antibiotics remains controversial. The role of biological therapies in mild to moderate disease has not been thoroughly evaluated and will not be discussed here.
Extraintestinal Manifestations of Crohn’s Disease
Authors: Juillerat Pascal , Mottet Christian , Froehlich Florian , Felley Christian , Vader John-Paul , Burnand Bernard , Gonvers Jean-Jacques , Michetti Pierre
Published: March 2005

In each case of extraintestinal manifestations of Crohn’s disease, active disease, if present, should be treated to induce remission, which may positively influence the course of most concomitant extraintestinal manifestations. For some extraintestinal manifestations, however, a specific treatment should be introduced. This latter part of disease management will be discussed in this chapter, in particular for pyoderma gangrenosum, uveitis, spondylarthropathy – axial arthropathy – and primarysclerosing cholangitis, which have also been described in quiescent Crohn’s disease. Few new drugs for the treatment of extraintestinal manifestations of Crohn’s disease have been developed in the past and only the role of infliximab has increased in Crohn’s disease-related extraintestinal manifestations. Drugs specifically aimed at this treatment, stemming from a few randomized controlled studies or case series, are sulfasalazine, 5-ASA, corticosteroids, azathioprine or 6-mercaptopurine, methotrexate, infliximab, dapsone and cyclosporine or tacrolimus.
Treatment of Gastroduodenal Crohn’s Disease
Authors: Mottet Christian , Juillerat Pascal , Gonvers Jean-Jacques , Michetti Pierre , Burnand Bernard , Vader John-Paul , Felley Christian , Froehlich Florian
Published: March 2005

Symptomatic gastroduodenal manifestations of Crohn’s disease (CD) are rare, with less than 4% of patients being clinically symptomatic. Gastroduodenal involvement may, however, be found endoscopically in 20% and in up to 40% of cases histologically, most frequently as Helicobacter pylori-negative focal gastritis, usually in patients with concomitant distal ileal disease. In practice, the activity of concomitant distal CD usually determines the indication for therapy, except in the presence of obstructive gastroduodenal symptoms. With the few data available, it seems correct to say that localized gastroduodenal disease should be treated with standard medical therapy used for more distal disease, with the exception of sulfasalazine and mesalanine with pH-dependent release. Presence of symptoms of obstruction needs aggressive therapy. If medical therapy with steroids and immunomodulatory drugs does not alleviate the symptoms, balloon dilation and surgery are the options to consider.
Pregnancy and Crohn’s Disease
Authors: Mottet Christian , Juillerat Pascal , Gonvers Jean-Jacques , Froehlich Florian , Burnand Bernard , Vader John-Paul , Michetti Pierre , Felley Christian
Published: March 2005

Crohn’s disease commonly affects women of childbearing age. Available data on Crohn’s disease and pregnancy show that women with Crohn’s disease can expect to conceive successfully, carry to term and deliver a healthy baby. Control of disease activity before conception and during pregnancy is critical, to optimize both maternal and fetal health. Generally speaking, pharmacological therapy for Crohn’s disease during pregnancy is similar to pharmacological therapy for non-pregnant patients. Patients maintained in remission by way of pharmacological therapy should continue it throughout their pregnancy. Most drugs, including sulfasalazine, mesalazine, corticosteroids, and immunosuppressors such as azathioprine and 6-mercaptopurine, are safe, whereas methotrexate is contraindicated.
Usefulness of Cardiac Troponin T and Echocardiography in the Diagnosis of Hypoxic Myocardial Injury of Full-Term Neonates
Authors: Szymankiewicz Marta , Matuszczak-Wleklak Marzena , Hodgman Joan E. , Gadzinowski Janusz
Published: March 2005

Background: Perinatal asphyxia constitutes a significant problem influencing neonatal mortality and morbidity. Objectives: The aim of the present work was to provide evidence of the usefulness of cardiac troponin T (cTnT) and echocardiographic investigations in the diagnosis of heart damage in full-term infants after intrauterine hypoxia. Material and Methods: The subjects were 39 asphyxiated and 44 term infants without fetal anoxia. Quantitative determinations of cTnT were performed between 12 and 24 h of life. Two-dimensional Doppler and color Doppler studies were performed at the bedside. We evaluated fractional shortening (FS), cardiac output (CO), cardiac index (CI), tricuspid (TI) and mitral (MI) insufficiency. Results: Asphyxiated infants presented increased cTnT (mean 0.141 ± 0.226 vs. 0.087 ± 0.111ng/ml; p < 0.01) and TI (38.5 vs. 11.4% of population; p < 0.05) compared to healthy infants. CO, CI and FS remained in the same range. Conclusions: We found cTnT to be the most useful among accessible diagnostic tools used in post-hypoxic heart damage in neonates. The data from our relatively small population study suggest a cTnT value of >0.1 ng/ml as a reliable marker of myocardial injury in neonates. Further study should be performed to generate a receiver-operator characteristic curve to discover what the cut-off level should be.
Cerebrovascular Disease as a Complication of Cardiac Transplantation
Authors: Belvís Robert , Martí-Fàbregas Joan , Cocho Dolores , García-Bargo María Dolores , Franquet Elisabeth , Agudo Rolando , Brosa Vicenç , Campreciós Marta , Puig Mireia , Martí-Vilalta Josep Lluis
Published: March 2005

Background and Objectives: To characterize the frequency, risk factors, clinical presentation and etiological subtypes of cerebrovascular diseases (CVD) following cardiac transplantation (CTX). Methods: In a retrospective review of our CTX database (period 1984–2002), we assessed demographic data, vascular risk factors, surgery and donor details. We classified ischemic stroke (IS) using the clinical criteria of the Oxfordshire Community Stroke Project and the etiological criteria of the TOAST study. Logistic regression analysis and survival curves were carried out. Results: CTX was performed in a total of 314 patients (age 46 ± 14 years, 78% male) and mean follow-up was 54 ± 57 months. Twenty-two patients (7%) presented CVD: hemorrhagic stroke in 12%, transient ischemic attack in 28% and IS in 60%. CVD were early postoperative (less than 2 weeks) in 20% of patients and late in 80%. The clinical presentation in patients with IS was total anterior circulation (23.1%), partial anterior (38.4%), lacunar (15.4%) and posterior circulation (23.1%), and the etiological classification was large artery atherosclerosis (15.4%), cardioembolism (14.4%), small vessel disease (15.4%), unusual causes (15.4%) and undetermined cause (38.4%). The only independent predictor of CVD was a prior CVD event with an odds ratio of 8.2 (95% CI, 2.2–30.2, p < 0.02). The estimated risk of CVD at 5 years was greater (p < 0.02) in patients with prior CVD (4.1%) than in those without (1.1%). Conclusions: CVD are a relatively frequent complication after CTX (7%) and usually occur in the late postoperative phase. CVD prior to transplantation increase the risk of CVD after this procedure.
Suppressive Effects of Iron on TGF-β1 Production by Renal Proximal Tubular Epithelial Cells
Authors: Horino Taro , Ito Hiroyuki , Yamaguchi Takuya , Furihata Mutsuo , Hashimoto Kozo
Published: March 2005

Background: TGF-β1, which is one of the profibrogenic cytokines, is considered essential for both the tubulointerstitial fibrosis found in chronic kidney diseases and the repair of tissue damage in acute renal injury. Iron plays an important part in inflammatory damage since it supplies cytotoxic hydroxyl radicals. The aim of the present study was to examine the direct effects of iron on TGF-β1 production and the expression of 8-hydroxy-2′-deoxyguanosine (8-OHdG), a marker of oxidative stress, by human renal proximal tubular epithelial cells (RPTEC). Methods: Using human RPTEC, TGF-β1 expression was studied by immunohistochemical staining, ELISA and RNase protection assays. 8-OHdG expression was evaluated by immunohistochemical staining. Results: Ferric iron suppressed both TGF-β1 secretion and mRNA expression, and enhanced 8-OHdG expression in RPTEC in a dose-dependent manner. Desferrioxamine, an iron chelator, eliminated the suppressive effect of ferric citrate on TGF-β1 production. Conclusions: The results suggest that iron may delay the repair of kidney injury during the acute inflammatory phase via a reduction in TGF-β1 production by RPTEC. Iron chelation may therefore be a useful strategy in the treatment of inflammatory kidney diseases.
Comparison of Cytotoxicity of Cysteine and Homocysteine for Renal Epithelial Cells
Authors: Nakanishi Takeshi , Akabane Eiko R. , Nanami Masayoshi , Kiyobayashi Yuri , Moriguchi Rintarou , Hasuike Yukiko , Otaki Yoshinaga , Miyagawa Koji , Itahana Reiko , Izumi Masaaki
Published: March 2005

Background: Although the cytotoxic effects of cysteine (Cys) on renal cells have been established, the effects of homocysteine (Hcy), which causes endothelial cell dysfunction, have not been well tested. We compared the direct toxicity of Hcy on renal tubular cells to that of Cys and examined the mechanism of cell toxicity. Methods: LLC-PK1 cells were incubated with test media containing 500 µM Cys or Hcy in the presence or absence of 100 µM copper. Lactate dehydrogenase release and thiobarbituric acid reactive substance were measured for estimating cytolysis and lipid peroxidation, respectively. The generation of hydrogen peroxide and hydroxyl radical, and the cell redox state were analyzed using the scopoletin method, salicylate-trap method, and glutathione (GSH) content, respectively. Superoxide dismutase, catalase, and vitamin E also were used for clarifying the mechanism of toxicity. Results: In the presence of copper (+ Cu), cytolysis at 16 h was more prominent in cells exposed to Cys than Hcy. In accordance with cytotoxicity, lipid peroxidation at 4 h of incubation, as well as hydrogen peroxide and hydroxyl radical formation in a shorter incubation, were remarkably greater in Cys + Cu than Hcy + Cu. The addition of Hcy, but not Cys, decreased GSH content significantly. Conclusion: In the presence of copper, Cys was extraordinarily more cytotoxic to renal cells than Hcy. Cytotoxicity from Hcy may be dependent upon depletion of cellular GSH, while Cys cytotoxicity is primarily dependent upon the generation of reactive oxygen species and lipid peroxidation.
Effects of Neutral pH and Reduced Glucose Degradation Products in a New Peritoneal Dialysis Solution on Morphology of Peritoneal Membrane in Rats
Authors: Ikehara Osamu , Nishimura Hideki , Naito Takashi , Higuchi Chieko , Sanaka Tsutomu
Published: March 2005

Background: In vitro studies have shown that pH and glucose degradation products (GDPs) in the dialysate are determinant factors for the biocompatibility of peritoneal dialysis (PD) treatment. The present study was thus designed to evaluate whether a newly developed PD solution, which features neutral pH levels and a low GDP concentration, influences tissue damage of the peritoneal membrane in an in vivo setting, and which factor is more critical to the histological changes. Methods: Rats were injected 3 times per day during 1 or 4 weeks with 10 ml of various PD fluids (group G, acidic pH, high GDPs; group S, neutral pH, low GDPs; or group A, acidic pH, low GDPs). When the experimental period was over, the mesothelial cell monolayers of the animals were taken and studied with population analysis, and peritoneal membranes were obtained from the abdominal wall for immunohistochemical examination with proliferating cell nuclear antigen (PCNA) and for measurement of thickness of the peritoneal specimens. Results: The density of the mesothelial cell monolayer and the number of fibroblast-like cells in group S were significantly less than in group G at 1 and 4 weeks’ injection. PCNA-positive nuclei in group S were significantly less than in group G for only the 1-week injection set (group G, 2.03 ± 0.95; group S, 0.85 ± 1.18 nuclei/1 × 104 µm2). At 4 weeks, the peritoneal thickness of group S (6.32 ± 0.53 µm) was significantly less than that of group G (7.94 ± 0.77 µm), There was no significant difference between groups S and A throughout the whole study period except for the result of the number of fibroblast-like cells. Conclusion: These results indicate that a PD solution with a neutral pH and low GDPs proved more biocompatible with the peritoneal membrane than a solution with an acidic pH and high GDPs. Furthermore, the level of the GDPs has more impact on tissue damage of the peritoneal membrane than the pH in the short term.
Pyruvate in the Correction of Intracellular Acidosis: A Metabolic Basis as a Novel Superior Buffer
Authors: Zhou Fang Qiang
Published: March 2005

The review focuses on biochemical metabolisms of conventional buffers and emphasizes advantages of sodium pyruvate (Pyr) in the correction of intracellular acidosis. Exogenous lactate (Lac) as an alternative of natural buffer, bicarbonate, consumes intracellular protons on an equimolar basis, regenerating bicarbonate anions in plasma while the completion of gluconeogenesis and/or oxidation occurs via tricarboxylic-acid cycle in mitochondria mainly in liver and kidney, or heart. The general assumption that Lac is ‘metabolized to bicarbonate’ in liver to serve as a buffer has been questioned. Pyr as a novel buffer would be superior to conventional ones in the correction of metabolic acidosis. Several likely biochemical mechanisms of Pyr action are discussed. Experimental evidence, in vivo, strongly suggested that Pyr would be particularly efficient in the correction of severe acidemia: type A lactic acidosis, hypercapnia with cardiac arrest, and diabetic and alcoholic ketoacidosis in animal experiments and clinic settings. Because of its multi-cytoprotection, Pyrs not only correct acidosis, but also benefit theunderlying dysfunction of vital organs. In addition, Pyr is also a potential buffer component of dialysis solutions. However, the instability of Pyr in aqueous solutions restricts its clinical applications as a therapeutic agent. Attempts to create a stable Pyr preparation are needed.
Dopamine D2-Receptor Activation Differentially Inhibits N- and R-Type Ca2+ Channels in Xenopus Melanotrope Cells
Authors: Zhang HongYan , Jenks Bruce G. , Ciccarelli Alessandro , Roubos Eric W. , Scheenen Wim J.J.M.
Published: March 2005

Dopamine inhibits pituitary melanotrope cells of the amphibian Xenopus laevis through activation of a dopamine (D2) receptor that couples to a Gi protein. Activated Gi protein subunits are known to affect voltage-operated Ca2+ currents (ICa). In the present study we investigated which Ca2+ currents are regulated by D2-receptor activation and which Gi protein subunits are involved. Whole-cell voltage-clamp patch-clamp experiments from holding potentials (HPs) of –80 and –30 mV show that 28.6 and 36.9%, respectively, of the total ICa was inhibited by apomorphin, a D2-receptor agonist. The inhibited current had fast activation and inactivation kinetics. From an HP of –80 mV, inhibition of N-type Ca2+ currents with ω-conotoxin GVIA and R-type current by SNX-482 reduced the efficacy of the apomorphin-induced inhibition. From an HP of –30 mV this reduction for ω-conotoxin GVIA was still observed. Blocking L-type current by nifedipine or P/Q-type current by ω-agatoxin IVA did not affect apomorphin-induced inhibition at either HP. Our results imply that D2-receptor activation inhibits both N- and R-type Ca2+ currents. Using a strong depolarizing pre-pulse partially reversed the inhibition of the total current by apomorphin. About 50% of this inhibition was achieved through interaction of Gβ/γ proteins, and this part of the inhibited ICa had fast activating and inactivating kinetics. However, the other part of the current inhibited by D2-receptor activation may proceed through Gα-PKA phosphorylation.
Clinicopathologic Study of Non-Hodgkin Lymphoma in Sinonasal and Hard Palate Regions in 15 Japanese Cases
Authors: Ikeda Tetsuya , Kanaya Takeo , Matsuda Akifumi , Motohashi Kenichi , Tanaka Hidekazu , Kohno Naoyuki , Kamiya Sigeru , Fujioka Yasunori , Kobayashi Ryo , Mizuno Fumio , Hasegawa Makoto
Published: March 2005

Non-Hodgkin lymphomas of the sinonasal region have been the subject of numerous studies. Previous reports have suggested that nasal lymphomas occurring in Orientals are mostly of the natural killer cell (NK)/T-cell phenotype which contrasts with the preponderance of the B-cell type in western populations. Recent studies indicated that NK/T-cell lymphoma constitutes the clinical condition of lethal midline granuloma. These reports led us to question whether all NK/T lymphomas are always lethal midline granuloma. We have investigated a series of 15 cases of non-Hodgkin lymphomas in the nasal and/or paranasal sinuses clinically, immunohistochemically and for the presence of Epstein-Barr virus (EBV). This study showed that the presence of EBV was common in nasal NK/T lymphoma, and this type of lymphoma was clearly highly frequent in other types of nasal lymphoma in our department. Moreover, in 4 cases of NK/T-cell lymphomas, the clinical features of lethal midline granuloma did not appear, indicating that NK/T lymphomas are not always lethal midline granuloma.
How Many Cravings? Pharmacological Aspects of Craving Treatment in Alcohol Addiction: A Review
Authors: Addolorato Giovanni , Abenavoli Ludovico , Leggio Lorenzo , Gasbarrini Giovanni
Published: March 2005

In the last decade, craving has increasingly been considered an important target for the treatment of patients with alcohol problems, and several drugs able to interfere with the neurotransmitters involved in craving mechanisms have been experimented. However, different subtypes of patients could have different mechanisms at the basis of alcohol craving. In this review, the main drugs currently used in the treatment of patients with alcohol problems are described. A hypothesis of pharmacological treatment of the different types of craving is also discussed.
Relationship between Disgust Sensitivity, Trait Anxiety and Brain Activity during Disgust Induction
Authors: Schienle Anne , Schäfer Axel , Stark Rudolf , Walter Bertram , Vaitl Dieter
Published: March 2005

We examined the influence of disgust sensitivity and trait anxiety on disgust processing via functional magnetic resonance imaging. Data of 63 healthy females were combined across four studies, where the same disgusting and affectively neutral pictures had been presented. The disgust pictures, rated as highly repulsive, provoked activation in the occipital cortex, the left prefrontal cortex and both amygdalae. Disgust sensitivity and trait anxiety were positively, and independently from each other, correlated with the activation of the right amygdala. This points to the role of the amygdala as an integrative brain structure, whose activation can be modulated by different affective styles.
Brain Glucocorticoid Receptor and Heat Shock Protein 70 Levels in Rats Exposed to Acute, Chronic or Combined Stress
Authors: Filipović Dragana , Gavrilović Ljubica , Dronjak Sladjana , Radojčić Marija B.
Published: March 2005

The pattern and intensity of glucocorticoid receptor (GR) and heat shock 70 protein (Hsp 70) changes in the hippocampus and brain cortex of adult Wistar rat males exposed to acute (immobilization, cold) and chronic (social isolation, crowding, daily swimming) stress or their combinations were followed by Western immunoblotting. Plasma ACTH and CORT were measured by chemiluminescent method and RIA. A significant decrease in cytosol GR and Hsp 70 was observed after acute stress, while chronic stresses led to negligible changes in both these proteins and caused a reduced responsiveness to a novel acute stress. This was valid irrespective of the type of chronic or acute stress combinations for both hippocampal and cortical GR and Hsp 70. The results support the hypothesis that chronic stress-induced deregulation of the LHPA axis may be caused, at least in part, by partial disruption of intracelullar negative feedback control in the higher centers of the brain.
Treatment with Dehydroepiandrosterone Prevents Oxidative Stress Induced by 3-Nitropropionic Acid in Synaptosomes
Authors: Túnez Isaac , Muñoz M. Carmen , Montilla Pedro
Published: March 2005

This study evaluates the antioxidative effect of dehydroepiandrosterone (DHEA) treatment on 3-nitropropionic acid (3-NPA)-induced oxidative stress in striatal and brain cortex synaptosomes. The oxidative derangement was confirmed by a high level of lipid peroxidation products and protein carbonyls, as well as by an enhanced superoxide dismutase activity (p < 0.001). These changes were partially prevented by DHEA. Moreover, 3-NPA induced a drop in succinate dehydrogenase activity, while DHEA treatment restored the succinate dehydrogenase activity. These results show that DHEA reduces oxidative stress in synaptosomes isolated from the brain of 3-NPA-treated rats, and they suggest this neurosteroid may protect mitochondrial and maintain synaptic integrity against damage induced by this acid.
Isoflavones Improve Plasma Homocysteine Status and Antioxidant Defense System in Healthy Young Men at Rest but Do Not Ameliorate Oxidative Stress Induced by 80% VO2pk Exercise
Authors: Chen Chung-Yen , Bakhiet Raga M. , Hart Vanessa , Holtzman Golde
Published: March 2005

Aims: (1) Determination of whether isoflavones, as antioxidants and estrogen-like substances, reduce the atherosclerotic process. (2) Assessment of isoflavone anti-atherosclerotic effectiveness by means of measuring plasma markers of atherosclerosis: homocysteine (Hcy), antioxidant status, and lipid peroxidation. (3) Testing of isoflavone antioxidant effectiveness in the presence and absence of oxidative stress induced by exercise. Methods: Thirty subjects paired by aerobic fitness level were randomly assigned to either a placebo or high-genistein isoflavone extract (HGI, 150 mg/day) treatment. Blood samples were collected before and within 5 min, after 30 min at 80% peak oxygen consumption (VO2pk) exercise, and before and after 4-week supplementation. Results: Plasma genistein and daidzein were significantly increased by 4-week HGI supplementation before and after exercise (p < 0.05). HGI decreased pre-exercise (pre-ex) plasma malondialdehyde (MDA) (p < 0.05) and Hcy (p = 0.01), and increased pre-ex blood total glutathione (TGSH) (p = 0.01), but did not diminish the increase of MDA and the decrease of TGSH due to the exercise. Furthermore, HGI supplementation enhanced pre-ex total antioxidant capacity (p < 0.05), but did not influence plasma vitamin C and E and uric acid concentrations. Conclusion: Isoflavones reduce plasma Hcy and have antioxidant activity in healthy young men. However, the effect of isoflavones on antioxidant systems may not be potent enough to diminish an abrupt surge of oxidative stress due to acute exercise.