bluuebunny/crossref_metadata_2025 huggingface dataset:
Endocannabinoid Signaling Negatively Modulates Stress-Induced Activation of the Hypothalamic-Pituitary-Adrenal Axis
Authors: Patel Sachin , Roelke Craig T. , Rademacher David J. , Cullinan William E. , Hillard Cecilia J.
Published: August 2004

Activation of the hypothalamic-pituitary-adrenal (HPA) axis is critical for the adaptation and survival of animals upon exposure to stressful stimuli, and data suggest that endocannabinoid (eCB) signaling modulates neuroendocrine function. We have explored the role of eCB signaling in the modulation of stress-induced HPA axis activation. Administration of the CB1 receptor antagonist/inverse agonist SR141716 (0.01, 0.1, 1, and 5 mg/kg, ip) to male mice produced a small, dose-dependent increase in the serum corticosterone (CORT) concentration. Despite this effect, the highest dose of SR141716 did not significantly increase neuronal activity within the paraventricular nucleus of the hypothalamus, as measured by the induction of Fos protein. Similarly, exposure of mice to 30 min of restraint increased serum CORT concentrations, but did not produce a consistent, statistically significant increase in Fos expression within the PVN. However, pretreatment of mice with SR141716 before restraint stress robustly potentiated restraint-induced CORT release and Fos expression within the PVN. Pretreatment of mice with either the CB1 receptor agonist CP55940, the eCB transport inhibitor AM404, or the fatty acid amide hydrolase inhibitor URB597 significantly decreased or eliminated restraint-induced CORT release. Upon exposure to acute restraint, hypothalamic 2-arachidonylglycerol content was reduced compared with the control value; however, after 5 d of restraint exposure (which resulted in an attenuated CORT response), the hypothalamic 2-arachidonylglycerol content was increased compared with the control value. These data indicate that eCB signaling negatively modulates HPA axis function in a context-dependent manner and suggest that pharmacological augmentation of eCB signaling could serve as a novel approach to the treatment of anxiety-related disorders.
Valproic Acid Inhibits Leptin Secretion and Reduces Leptin Messenger Ribonucleic Acid Levels in Adipocytes
Authors: Lagace Diane C. , McLeod Roger S. , Nachtigal Mark W.
Published: August 2004

Treatment of epilepsy or bipolar disorder with valproic acid (VPA) induces weight gain and increased serum levels for the satiety hormone, leptin, through an unidentified mechanism. In this study we tested the effects of VPA, a short-chain branched fatty acid (C8:0), on leptin biology and fatty acid metabolism in 3T3-L1 adipocytes. VPA significantly reduced leptin secretion in a dose-dependent manner. Because fatty acid accumulation has been hypothesized to block leptin secretion, we tested the effect of VPA on fatty acid metabolism. Using 14C-radiolabeled VPA, we found that the 14C was mainly incorporated into triacylglycerol. VPA did not alter lipogenesis from acetate, nor did it change the amount of intracellular free fatty acids available for triacylglycerol synthesis. Decreased leptin secretion was accompanied by a reduction in leptin mRNA, even though VPA treatment did not alter the protein levels for known transcription factors affecting leptin transcription including: CCAAT/enhancer binding protein-α, peroxisome proliferator-activated receptor-γ, or steroid regulatory element binding protein 1a. VPA altered levels of leptin mRNA independent of de novo protein synthesis without affecting leptin mRNA degradation. This report demonstrates that VPA decreases leptin secretion and mRNA levels in adipocytes in vitro, suggesting that VPA therapy may be associated with altered leptin homeostasis contributing to weight gain in vivo.
Characterization of the Human Corticotropin-Releasing Factor2(a) Receptor Promoter: Regulation by Glucocorticoids and the Cyclic Adenosine 5′-Monophosphate Pathway
Authors: Nanda Steven A. , Roseboom Patrick H. , Nash George A. , Speers James M. , Kalin Ned H.
Published: August 2004

Corticotropin-releasing factor (CRF) is a neurotransmitter and hormone believed to integrate responses to stress. Evidence suggests central CRF systems are overactive in some individuals suffering from depression and anxiety disorders. CRF receptor antagonism blocks stress-induced endocrine, autonomic, and behavioral effects in animal models, and studies have implicated the CRF2 receptor in anxiety-related behaviors. Greater understanding of the regulation of CRF2 expression may facilitate understanding mechanisms underlying anxiety. The present studies are the first to characterize the transcriptional regulation of the human CRF2(a), the predominant CRF2 isoform in brain. Four kilobase pairs of sequence immediately upstream of the first exon of CRF2(a) represented our full-length promoter region. Sequentially smaller fragments of the CRF2(a) promoter region were generated by PCR and cloned upstream of a luciferase reporter gene. Expression was monitored from these constructs within Chinese hamster ovary-K1 cells and within rat aortic A7R5 cells that express CRF2. Glucocorticoid treatment decreased expression and elevating intracellular cAMP increased expression from the human CRF2(a) promoter. The regions of the CRF2(a) promoter that regulate the inducible expression were determined, and the functional cAMP response element and glucocorticoid response element cis-regulatory elements within these regions were identified using a combination of site-directed mutagenesis and EMSAs. Given the possibility of species-specific differences in gene expression, interpretation of gene expression studies from rat and mouse model systems is difficult. Examination of expression from the human CRF2(a) promoter will provide insight into these model systems and may translate more readily to the development of therapeutics to treat human psychiatric illness.
TGFβ/BMP activate the smooth muscle/bone differentiation programs in mesoangioblasts
Authors: Tagliafico Enrico , Brunelli Silvia , Bergamaschi Anna , De Angelis Luciana , Scardigli Raffaella , Galli Daniela , Battini Renata , Bianco Paolo , Ferrari Sergio , Cossu Giulio , Ferrari Stefano
Published: August 2004

Mesoangioblasts are vessel-derived stem cells that can be induced to differentiate into different cell types of the mesoderm such as muscle and bone. The gene expression profile of four clonal derived lines of mesoangioblasts was determined by DNA micro-array analysis: it was similar in the four lines but different from 10T1/2 embryonic fibroblasts, used as comparison. Many known genes expressed by mesoangioblasts belong to response pathways to developmental signalling molecules, such as Wnt or TGFβ/BMP. Interestingly, mesoangioblasts express receptors of the TGFβ/BMP family and several Smads and, accordingly, differentiate very efficiently into smooth muscle cells in response to TGFβ and into osteoblasts in response to BMP. In addition, insulin signalling promotes adipogenic differentiation, possibly through the activation of IGF-R. Several Wnts and Frizzled, Dishevelled and Tcfs are expressed, suggesting the existence of an autocrine loop for proliferation and indeed, forced expression of Frzb-1 inhibits cell division. Mesoangioblasts also express many neuro-ectodermal genes and yet undergo only abortive neurogenesis, even after forced expression of neurogenin 1 or 2, MASH or NeuroD. Finally, mesoangioblasts express several pro-inflammatory genes, cytokines and cytokine receptors, which may explain their ability to be recruited by tissue inflammation. Our data define a unique phenotype for mesoangioblasts, explain several of their biological features and set the basis for future functional studies on the role of these cells in tissue histogenesis and repair.
Critical role of N-cadherin in myofibroblast invasion and migration in vitro stimulated by colon-cancer-cell-derived TGF-β or wounding
Authors: De Wever Olivier , Westbroek Wendy , Verloes An , Bloemen Nele , Bracke Marc , Gespach Christian , Bruyneel Erik , Mareel Marc
Published: August 2004

Invasion of stromal host cells, such as myofibroblasts, into the epithelial cancer compartment may precede epithelial cancer invasion into the stroma. We investigated how colon cancer-derived myofibroblasts invade extracellular matrices in vitro in the presence of colon cancer cells. Myofibroblast spheroids invade collagen type I in a stellate pattern to form a dendritic network of extensions upon co-culture with HCT-8/E11 colon cancer cells. Single myofibroblasts also invade Matrigel™ when stimulated by HCT-8/E11 colon cancer cells. The confrontation of cancer cells with extracellular matrices and myofibroblasts, showed that cancer-cell-derived transforming growth factor-β (TGF-β) is required and sufficient for invasion of myofibroblasts. In myofibroblasts, N-cadherin expressed at the tips of filopodia is upregulated by TGF-β. Functional N-cadherin activity is implicated in TGF-β stimulated invasion as evidenced by the neutralizing anti-N-cadherin monoclonal antibody (GC-4 mAb), and specific N-cadherin knock-down by short interference RNA (siRNA). TGF-β1 stimulates Jun N-terminal kinase (also known as stress-activated protein kinase) (JNK) activity in myofibroblasts. Pharmacological inhibition of JNK alleviates TGF-β stimulated invasion, N-cadherin expression and wound healing migration. Neutralization of N-cadherin activity by the GC-4 or by a 10-mer N-cadherin peptide or by siRNA reduces directional migration, filopodia formation, polarization and Golgi-complex reorientation during wound healing. Taken together, our study identifies a new mechanism in which cancer cells contribute to the coordination of invasion of stromal myofibroblasts.
Screening tests for abnormalities of the protein C anticoagulant pathway / Suchteste für Anomalien im antikoagulatorischen Protein C-System
Authors: Schambeck Ch. M.
Published: August 2004

There is an increasing demand for a rational diagnosis of
patients with thrombophilia by clinical laboratories. The
protein C pathway plays an important part in this system.
To rationalize the diagnostics, methods have been introduced
to test the anticoagulant capacity of the whole
protein C pathway. These screening assays should reliably
detect a factor V Leiden mutation, protein C and S
deficiency. These assays differ in detection methods,
interfering factors and even in their responsiveness to
protein S. The methodological approach is based on the
activation of endogenous plasma protein C by a snake
venom extract. Clincial evaluations demonstrated the
validity of these tests to screen for a factor V Leiden
mutation and protein C deficiency. Protein S deficiency
cannot be identified sufficiently. The assays, however,
seem to have additional positive effects. They could be
used to assess the risk for thrombosis in the future. Initial
studies confirm this hypothesis. Hence, a positive test
result in protein S-deficient patients correlated with a
higher risk for thrombosis.
Ein Modell zur Lieferantenbewertung im medizinischen Laboratorium / A Model for the evaluation of suppliers in medical laboratories
Authors: Kern S. , Hubmann M. , Semmelrock H.-J. , Tiran A.
Published: August 2004

Periodic evaluation of suppliers is an integral component
of all relevant quality management systems established
in medical laboratories. Performing such evaluation is
always laborious, but rarely entails a perceptible benefit
for laboratories and their suppliers. Therefore, we worked
out 19 criteria for the assessment of suppliers and a
model for the analysis of results in cooperation with 5
representative manufacturers for in vitro diagnostics and
11 medical laboratories. The criteria consider the special
needs of medical laboratories combined with an effective
procedure for continual quality improvement. In a pilot
scheme the model was evaluated for its suitability in
practical use. Various methods for data analysis enable
suppliers to get relevant information about individual and
collective customer satisfaction. In the case of centralised
data collection and analysis a suitable tool for
benchmarking is available.
Diagnostik von Chlamydien-Infektionen / Diagnosis of chlamydial infections
Authors: Schütt S. , Essig A.
Published: August 2004

Chlamydiae are obligate intracellular bacteria undergoing
a unique growth cycle which is important for the special
features of diagnosis, therapy and pathogenesis of chlamydial
infections. Mainly Chlamydia trachomatis, Chlamydia
pneumoniae and Chlamydia psittaci cause
infections in humans. The clinical relevance of chlamydia-
like species such as Simkania, Waddlia and Parachlamydia
is unclear and currently under investigation. In
principle, laboratory diagnosis of chlamydial infections
can be achieved by direct detection of the organisms
from clinical specimens and antibody detection. The
selection of suitable laboratory tests depends on the
chlamydial species and the clinical presentation of infection.
Culture tests have been proven to be highly specific,
however due to the high level of technical expertise necessary,
chlamydial cultures are generally performed in
specialized reference laboratories. Nucleic acid amplification
technologies are characterized by their high sensitivity
and have been broadly evaluated for the detection
of C. trachomatis from urogenital specimens. In contrast,
standardization of DNA amplification methods for detection
of C. pneumonia is urgently needed to evaluate the
importance of the organism in respiratory diseases, as
well as in associated extrapulmonary diseases like atherosclerosis.
Serodiagnosis of chlamydial infections
should be based on species-specific methods like the
technically demanding microimmunofluorescence test
(MIF). Commercially developed MIF assays, peptidebased
EIAs and immunoblot assays are still in a phase
of evaluation and may contribute to a more standardized
serodiagnosis of Chlamydia infections.
Anwendungsgebiete der Massenspektrometrie in der Klinischen Chemie und Laboratoriumsmedizin / Application of mass spectrometry in clinical chemistry and laboratory medicine
Authors: Fiedler G.M. , Ceglarek U. , Lembcke J. , Baumann S. , Leichtle A. , Thiery J.
Published: August 2004

The use of mass spectrometry (MS) as an analytical tool
becomes increasingly important in clinical laboratory
diagnostics. In the last decade there has been an exponential
growth in clinical laboratory, pharmacology, and
toxicology applications. At present, the spectrum of MS
applications ranges from the measurement of single analytes
to qualitative and quantitative multiparametric
analyses.

Combining tandem mass spectrometry with atmospheric
pressure ionization techniques offers high analytic
sensitivity and specificity, robustness, and the option for
high throughput analyses at low running costs. Today,
this analytical platform is already used in routine clinical
laboratory to screen for inherited metabolic disorders in
newborns, for therapeutic drug monitoring, and for hormone
profiling. In addition, SELDI-TOF and MALDI-TOF
techniques are used for clinical proteomic pattern diagnostics.
This short review will give an overview of the
current status of mass spectrometry techniques, established
applications in clinical laboratory diagnostics, and
the perspectives for future developments in laboratory
medicine.
DNA methylation analysis: a promising diagnostic tool / DNA-Methylierungs-Analyse: ein vielversprechendes diagnostisches Werkzeug
Authors: Schuster M.
Published: August 2004

Since the investigation of molecular biological mechanisms
was extended to the genomic level and after the
sequence of the human genome was established, interest
in DNA-based diagnostics has increased tremendously.
While most research is currently being devoted
to the discovery and clinical application of genetic, proteomic
and RNA expression markers, DNA methylation
is rapidly emerging as a new level of cellular information
with biomarker potential. DNA methylation is involved in
the regulation of gene activity. Aberrant DNA methylation
has been associated with a variety of human diseases.
As such, DNA methylation markers hold a great promise
as a diagnostic tool, e.g. in early cancer screening [1].
Methods are available for the genome-wide discovery of
methylation markers that differentiate between different
types of tissue samples. In contrast to expression markers,
DNA methylation markers are accessible at the DNA
level, which enables their analysis even in archived paraffin-
embedded tissue samples. Methods are available to
detect a few copies of aberrantly methylated DNA in a
background of a vast excess of normally methylated
DNA, which is the prerequisite for assaying methylation
markers also in body fluids that are readily accessible in
clinical practice.
Trace Analysis of Peroxide Explosives by High Performance Liquid Chromatography-Atmospheric Pressure Chemical Ionization-Tandem Mass Spectrometry (HPLC-APCI-MS/MS) for Forensic Applications
Authors: Xu X , van de Craats AM , Kok EM , de Bruyn PCAM
Published: August 2004

An HPLC-APCI-MS(/MS) method for the (trace) analysis of the most commonly encountered peroxide explosives, hexamethylenetriperoxidediamine (HMTD) and triacetonetriperoxide (TATP), has been developed. With this method, HMTD and TATP have been analyzed in the same run. (Pseudo-)molecular ions of these peroxides have been obtained as base peak under the same condition. A series of product ions was produced from these pseudo-molecular ions ([HMTD-1]+ and [TATP + NH4]+) in the MS/MS analysis. We also pioneeredin showing that TATP molecular ion [TATP-H]+ can be observed with HPLC-MS/MS. The limit of detection for HMTD and TATP was 0.26 and 3.3 ng, respectively, on column by HPLC-MS in the Full Scan mode and 0.08 and 0.8, respectively, by HPLC-APCI-MS/MS in Selected Reaction Monitoring (single ass unit) mode. The method presented has been applied successfully for the identification of peroxides in the bulk solid state (powder sample), as well as in post-blast extracts originating from a forensic case. For the post-blast extracts, the use of tandem MS has been shown clearly to be of crucial importance for the identification and detection of the peroxide explosives.
Y-Chromosome STR System, Y-PLEX™ 12, for Forensic Casework: Development and Validation
Authors: Shewale JG , Nasir H , Schneida E , Gross AM , Budowle B , Sinha SK
Published: August 2004

The Y-PLEX™ 12 system, developed for use in human identification, enables simultaneous amplification of eleven polymorphic short tandem repeat (STR) loci, namely DYS392, DYS390, DYS385 a/b, DYS393, DYS389I, DYS391, DYS389II, DYS19, DYS439 and DYS438, residing on the Y chromosome and Amelogenin. Amelogenin provides results for gender identification and serves as internal control for PCR. The validation studies were performed according to the DNA Advisory Board's (DAB) Quality Assurance Standards. The minimal sensitivity of the Y-PLEX™ 12 system was 0.1 ng of male DNA. The mean stutter values ranged between 3.76–15.72%. A full male profile was observed in mixture samples containing 0.5 ng of male DNA and up to 400 ng of female DNA. Amelogenin did not adversely affect the amplification of Y-STRs in mixture samples containing male and female DNA. The primers for the Y-STR loci present in Y-PLEX™ 12 are specific for human DNA and some higher primates. None of the primate samples tested provided a complete profile at all 11 Y-STR loci amplified with the Y-PLEX™ 12 system. Y-PLEX™ 12 is a sensitive, valid, reliable, and robust multiplex system for forensic analysis, and it can be used in human forensic and male lineage identification cases.
Common Mitochondrial DNA Deletion Associated With Sudden Natural Death in Adults
Authors: Polisecki EY , Schreier LE , Ravioli J , Corach D
Published: August 2004

One of the most frequent causes of death in developed countries is sudden natural death (SND), which is the most common indication for medico-legal autopsies. Cardiac diseases are frequently detected among SND. Mitochondrial DNA (mtDNA) is easily damaged by reactive oxygen species, and it may cause dysfunction in tissues, leading to early events in cardiovascular disease. A specific mtDNA deletion of 4977 bp is associated to aging, myocardial dysfunction, and bioenergetic deficit. The potential link between mtDNA damage and SND has not been investigated before. Our aim was to evaluate the accumulation of the common mtDNA4977-deletion in cardiac muscle samples from autopsies of SND in adults (n = 14) in comparison to control samples from unnatural deaths (n = 12). Serial dilution-polymerase chain reaction method was performed to estimate the proportion of the total mtDNA harboring the mtDNA4977-deletion. Coefficient variation intra-assay was 8%, and inter-assay was 12%. MtDNA4977-deletion percentage was higher in samples obtained from victims of SND than in those from subjects who died of unnatural causes (p < 0.05). No differences in mtDNA4977-deletion were found between SND victims 39–51 years old, and no correlation was found between these samples and age, r = 0.30, p = 0.29 while it was significant among control samples, r = 0.68, p < 0.05. The association between mtDNA4977 deletion with SND victims might offer a tool to provide additional information to clarify complex SND investigations.
Population Genetic Data at Two Minisatellites (D19S20 and APOB 3' VNTR) Between Two Tribal Populations From Central India
Authors: Das B , Seshadri M
Published: August 2004

Two minisatellites (D19S20 and ApoB 3' VNTR) have been analyzed among two anthropologically distinct tribal populations from Bastar district of Madhya Pradesh in Central India, namely Bison Horn Maria and Muria. DNA typing was carried out on a total of 54 individuals for D19S20 minisatellite and 79 individuals for ApoB 3' VNTR.
Distribution of Allele Frequencies of a STR (D5S580) Marker in Five Population Groups of Kerala in South India
Authors: Khurana S , Seshadri M
Published: August 2004

Ezhavas, Muslims, Arayas, Nairs, and Vishwakarmas of the Kerala state in south India for a STR marker (D5S580).
Immunohistochemical localization of androgen receptors in the urogenital tracts of human embryos
Authors: Sajjad Yasmin , Quenby Siobhan , Nickson Paul , Lewis-Jones D Iwan , Vince Gill
Published: August 2004

The aim of this study was to investigate androgen receptor (AR) expression in the developing human urogenital tract. The distribution of AR was examined in paraffin-embedded tissue sections of the lower urogenital tract using 55 human embryos of 8–12 weeks of gestation. Immunohistochemistry was performed for AR detection and gender was determined by polymerized chain reaction. There were no differences in the distribution of AR in male and female embryos at any stage of gestation. AR was present only in the mesenchymal tissues of the urogenital sinus at 8 weeks whilst the epithelium was negative, but after 9 weeks the epithelium also showed progressively more positive staining. In the phallus, AR staining was prominent. There was far less staining in the epithelium of the urethral groove from 8 to 10 weeks, whilst the mesenchyme of the urethral folds showed positive staining. At 11 and 12 weeks, both the urethral groove and folds showed uniform staining. The genital tubercle, genital swelling and bulbourethral gland precusors were also positively stained, although paramesonephric ducts were negative. Staining was observed in the mesonephric duct from 9 weeks. There was an absence of staining in the rectum at all stages of gestation. The expression of AR in an epithelium may be dependent upon the mesenchyme. Mesenchymal–epithelial interactions played an important role in development, as has been described in experimental animals. AR expression could play a part in the growth of the genital organs.
EGF-induced trophoblast secretion of MMP-9 and TIMP-1 involves activation of both PI3K and MAPK signalling pathways
Authors: Qiu Q , Yang M , Tsang B K , Gruslin A
Published: August 2004

Epidermal growth factor (EGF) is present in the maternal-fetal environment and has an important role in placental development. Matrix metalloproteinase-9 (MMP-9) expression/activation is a pre-requisite in extravillous trophoblast invasion. Whereas EGF up-regulates MMP-9 activity in a variety of cell types, there is no direct evidence for the stimulation of MMP-9 and tissue inhibitor of metalloproteinase-1 (TIMP-1) secretion by EGF in extravillous trophoblasts. In addition, the signalling pathways involved in this regulation are not clear. In the present study, we have examined the possible involvement of the phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways in the regulation of the MMP-9/TIMP-1 system by EGFin vitro. We used a well-established invasive extravillous trophoblast cell line (HTR8/Svneo) and measured gene and protein expression by semi-quantitative RT-PCR and western analysis respectively. MMP activity was determined by zymography. We showed for the first time that EGF activated both PI3K/Akt and MAPK/extracellular-signal regulated kinase (ERK) signalling in HTR8/SVneo, and increased both MMP-9 and TIMP-1 mRNAs and protein concentrations. Interfering with either signalling pathway via PI3K inhibitor LY294002 or MEK inhibitor U0126 in EGF-stimulated HTR8/SVneo cells blocked the induction of MMP-9 and TIMP-1. LY294002 inhibited Akt phosphorylation, but had no effect on ERK phosphorylation; U0126 suppressed ERK phosphorylation without interfering with the phosphorylation of Akt. In addition, expression of constitutively active Akt (Myr-Akt1, Myr-Akt2, Myr-Akt3) was not sufficient to induce proMMP-9 and TIMP-1 secretion. Our results suggest that the activation of both PI3K and MAPK pathways in extravillous trophoblasts is necessary for the up-regulation of MMP-9 and TIMP-1 expression by EGF.
Mitochondria in human oogenesis and preimplantation embryogenesis: engines of metabolism, ionic regulation and developmental competence
Authors: Van Blerkom Jonathan
Published: August 2004

Mitochondria are the most abundant organelles in the mammalian oocyte and early embryo. While their role in ATP production has long been known, only recently has their contribution to oocyte and embryo competence been investigated in the human. This review considers whether such factors as mitochondrial complement size, mitochondrial DNA copy numbers and defects, levels of respiration, and stage-specific spatial distribution, influence the developmental normality and viability of human oocytes and preimplantation-stage embryos. The finding that mitochondrial polarity can differ within and between oocytes and embryos and that these organelles may participate in the regulation of intracellular Ca2+homeostasis are discussed in the context of how focal domains of differential respiration and intracellular-free Ca2+regulation may arise in early development and what functional implications this may have for preimplantation embryogenesis and developmental competence after implantation.
Deadly decisions: the role of genes regulating programmed cell death in human preimplantation embryo development
Authors: Jurisicova Andrea , Acton Beth M
Published: August 2004

Human preimplantation embryo development is prone to high rates of early embryo wastage, particularly under currentin vitroculture conditions. There are many possible underlying causes for embryo demise, including DNA damage, poor embryo metabolism and the effect of suboptimal culture media, all of which could result in an imbalance in gene expression and the failed execution of basic embryonic decisions. In view of the complex interactions involved in embryo development, a thorough understanding of these parameters is essential to improving embryo quality. An increasing body of evidence indicates that cell fate (i.e. survival/differentiation or death) is determined by the outcome of specific intracellular interactions between pro- and anti-apoptotic proteins, many of which are expressed during oocyte and preimplantation embryo development. The recent availability of mutant mice lacking expression of various genes involved in the regulation of cell survival has enabled rapid progress towards identifying those molecules that are functionally important for normal oocyte and preimplantation embryo development. In this review we will discuss the current understanding of the regulation of cell death gene expression during preimplantation embryo development, with a focus on human embryology and a discussion of animal models where appropriate.
Mapping of genes regulating abiotic stress tolerance in cereals
Authors: Galiba G.
Published: August 2004

The location of major QTLs or even genes controlling abiotic stress tolerance is now possible by the application of marker-mediated techniques. This is achieved by exploiting precise genetic stocks, such as doubled haploids (DHs), recombinant substitution lines (RSLs) and recombinant inbred lines (RILs), along with the comprehensive genetic maps now available through the application of molecular marker techniques. These strategies are illustrated here showing how QTLs/genes affecting vernalization response, cold tolerance, osmotic adjustment, osmolite accumulation (free amino acids, polyamines and carbohydrates), salt tolerance and cold-regulated protein accumulation have been identified and located. Also, an example of marker-assisted selection (MAS) for frost tolerance is presented. Major loci and QTLs affecting stress tolerance inTriticeaehave been mapped on the group 5 chromosomes, where the highest concentration of abiotic stress-related QTLs (vernalization response, frost tolerance, salt tolerance and osmolite accumulation) was located. A conserved region with a major role in osmotic adjustment has been located on the group 7 chromosomes.
Marker-assisted breeding for the improvement of disease resistance in cereal crops
Authors: Bürstmayr H.
Published: August 2004

Recent reviews on molecular markers developed for wheat genes have been published by Langridge and Chalmers (1998) and Gupta et al. (1999), while updated lists are maintained in the catalogue of gene symbols for wheat (http://wheat.pw.usda.gov/ggpages/pubs.shtml).
Nitrate content in lettuce (Lactuca sativa L.) grown on aeroponics with different quantities of nitrogen in the nutrient solution
Authors: Kacjan-Maršić N. , Osvald J.
Published: August 2004

The influence of different quantities of nitrogen in the nutrient solution on growth, development and nitrate content was studied in aeroponically grown lettuce (Lactuca sativa L.). Three successive experiments were conducted in 1999 from April to September, in an aeroponic system. The lettuce plants, cv. Vanity, were grown in aeroponics using four different amounts of nitrogen in the nutrient solutions. The pH level was maintained between 5.5 and 6.5, and the EC between 1.8 and 2.2 mS/cm. Fresh weight measurements were made on all the material. The differences between the mean fresh shoot weights were statistically significant in all three experiments. In the first experiment, the maximum final fresh weight in the treatment with 8 mM nitrogen averaged 999.0 g. In the second and third experiments the largest amount of nitrogen, 12 mM NO3-N, significantly (p<0.05) increased the fresh shoot weight of lettuce plants. low levels of nitrate in the nutrient solution (4 mM NO3-N in the first and 1.2 mM NO3-N in the second aeroponic experiment) significantly (p<0.05) increased the fresh weight of the final roots compared with the level of nitrate in standard nutrient solution (12 mM NO3-N). The differences between the means for plant height were statistically significant (p<0.05) in all three experiments. In the first and third experiments the lengths of the primary roots of the lettuce plants were significantly (p<0.05) influenced by different NO3-N concentrations in the nutrient solution. The highest NO3- concentration in the lettuce leaves was recorded in plants grown in nutrient solutions with the highest NO3-N concentration (17 mM in the first, 12 mM in the second and third experiments). An acceptably low NO3- concentration was found in the leaves of lettuce treated containing with nutrient solution 4 mM NO3-N in all three experiments.
Analysis of 0.01 M CaCl 2 Soluble Organic Nitrogen in the Treatments of Westsik's Crop Rotation Experiment
Authors: Lazányi János , Loch J. , Jászberényi I.
Published: August 2004

Current concerns about
soil and water quality deterioration, limited possibility of fossil fuels, loss
of biodiversity, and in general the viability of rural communities urge to work
out methods of sustainable agriculture in the Nyírség region of Hungary. Sustainable
agriculture seeks solutions for environmental, economic and agricultural
problems at the same time. The aim is to develop new production methods which
provide the protection of nature. In sustainable agricultural systems the
management of organic matters and, more widely, the whole nutrient management
are based on the total self-sufficiency of the farm. The entire cycle of
organic matter production and decomposition takes place within the farm
boundaries and makes the farm an actual biological system. The rate of
metabolism and the organic matter cycle are characteristic features of each
farm and define their activity for a long time. Present investigation
conducted in Westsik's crop rotation experiment has found a highly significant
correlation between organic nitrogen extracted by 0.01
M
CaCl
2

solution and potato yield. It has shown that soil organic nitrogen extracted by
0.01
M
CaCl
2
solution is a reliable indicator of nitrogen
available for mineralization during the growing season. When precise nitrogen
fertilizer recommendations are required, the method can supply additional
information for environmentally friendly, sustainable agriculture.
Phospholipid Fatty Acid (PLFA) Analysis of Rhizosphere Bacterial Communities in a Peat Soil
Authors: Halbritter András , Mogyoróssy T.
Published: August 2004

To analyze the rhizosphere bacterial communities in
wetlands, the total lipid content was extracted from a peat soil and 4 abundant
wetland plant roots (
Typha angustifolia
L.,
Salix cinerea
L.,

Carex pseudocyperus
L.,
Thelypteris palustris
Salisb.). The
separated phospholipid fraction was further fractionated and deriva­tized prior
to gas chromatography-mass spectrometry (GC-MS) measurement. In the evaluation
only the bacteria-specific fatty acids were used in order to neglect fatty acid
information derived from plant root cells. Based on these analyses, a high
level bacterial concentration was demonstrated in the rhizosphere, and the
relative occurrence of aerobe and anaerobe, Gram positive and negative
bacteria, methanotrophs, sulphate reducers and Actinobacteria was determined.
Through the PLFA analysis the study of bacteria regardless of culturability was
possible.
Nitrogen Transformation Processes Taking Place During the Intensive Phase of Composting
Authors: Alexa László , Füleky Gy.
Published: August 2004

N transformation
processes taking place during the intensive phase of composting were analyzed
for characteristic compost raw materials in an adiabatic composting bioreactor
by analyzing composts (in various stages of maturity), emitted gases and
leakage water.  Temperature exhibited a
similar curve for all raw materials, with a gradual decrease in compost
temperature from day 11-13 on. Measurements of NH
3
indicated a
significant difference between the various raw materials, sometimes amounting
to an order of magnitude, in the quantitative data of NH
4

volatilization. Analysis of leakage water indicated that ammonification and
nitrification processes could be traced satisfactorily, but the quantity of
leakage water formed in the adiabatic drum composter and the associated N
losses were negligible compared to the total N cycle of compost formation.
Analysis of the composts showed that the organic matter content of the samples
declined during composting as the result of biodegradation.
Specific Weed Tolerance of Wheat (Triticum aestivum L.) Varieties - A Key to Non-chemical Weed Control
Authors: Kassai Katalin M. , Szentpétery Z. , Hegedüs Z. ,   et al.
Published: August 2004

Six
wheat varieties representing different genotypes were tested under exposed and
protected conditions in a three year herbicide provocation field trial at Nagygombos,
Hungary. Three types of herbicide treatments (fluroxipir, bromoxynil and dicamba
ai.) were applied in comparison with untreated and mechanical treated controls.
Weed populations were sorted into two major groups according to the level of
their occurrence. The result of experimental treatments were evaluated and  weed tolerance of varieties was determined. The
magnitude of weed populations has shown significant differences. All weed
control treatments, including chemical and mechanical applications, had an
influence on weed development. Herbicide treatments had about fifty per cent,
while mechanical applications had a nearly hundred per cent effect concerning
weed reduction. The latter can be considered as a level of total weed extinction.
High weed canopies were observed in the case of untreated controls only. Wheat
cultivars have shown a variety specific yield response. The results obtained suggest
varietal differences concerning weed tolerance. The extent of yield losses
between wheat cultivars ranged from 4 to 18 per cent of grain yield. In the
trial Martonvásári 19 and Martonvásári 21 wheat varieties were proven to have
the best weed tolerance abilities.
Compilation of a Watershed Level, Complex Land Information System for Internet Service
Authors: Szabó József
Published: August 2004

Rearrangement of land resources following the political changes in
Hungary has not ended yet. It is almost impossible to collect information
necessary for planning activities on outer areas of settlements. The data are
either distributed among various organizations where they can be found in
diverse forms, or are not available at all. 
Water quality protection, however, has become legally ordered concerning
municipal activities around the Lake Balaton. This region is considered as the
most important recreation area and tourist target in Hungary and is also
affected by a number of factors providing sources to environmental conflicts.
Settlements of a watershed (Tetves Creek) on the southern shoreline of Lake
Balaton (Central Hungary) tendered a complex task for collecting the sources of
the authentic data of the Hungarian rural areas along with systematizing and
saving these data in a uniform GIS. An application using Autodesk MapGuide has
been developed for Internet realization. The implemented web based GI system
can be used in Internet and Intranet environment.
Characterization of the Nutrient Buffer Capacity of K, Ca, Mg in Two Hungarian Soils
Authors: Filep Tibor
Published: August 2004

Changes in the K,
Ca and Mg contents of the soil solution were examined during the growing period
to characterize the nutrient buffer capacity of sandy and clay loam soils in
pot experiments set up with Italian ryegrass as indicator plant. 
K,
Ca and Mg concentrations in the soil solution decreased during the growth due
to the nutrient uptake by plants. The
normalized values of decrease

(expressing the change in the concentration of the given element during unit
time) were close to each other for Ca and Mg, while there was a significant
difference between the sandy and clay loam soil in the case of K (0.65 and
0.11, respectively). We assumed that the normalized value was inversely
proportional to the nutrient buffer capacity of soils.  For the comparison of experiments conducted
under different conditions the
UPI (uptake index) values
were
introduced. The UPI value shows to what extent the amount of the given ion
calculated from concentration decrease in the soil solution accounts for the
amount of element taken up by the plant. The amount of K depleted from the soil
solution was 19% of the K amount taken up on the sandy soil, while on the clay
loam this value was only 0.8%. Because the UPI values from experiments under
different environments are comparable, they characterized the nutrient buffer
capacity of soils better than the normalized values of decrease.
Műtrágyázás hatása a mustár termésére és elemfelvételére
Authors: Kádár Imre
Published: August 2004

Karbonátos vályog csernozjom talajon, egy műtrágyázási tartamkísérlet 12. évében vizsgáltuk az eltérő N-, P- és K-ellátottsági szintek és kombinációik hatását a dán eredetű (Budakalászi sárga fajta) mustár szerveinek ásványi összetételére a tenyészidő és a talaj NPK-kínálata függvényében. Javaslatokat fogalmaztunk meg a növény tápláltsági állapotát jellemző diagnosztikai határkoncentrációkra, valamint a tervezett termés elemszükségletét kifejező fajlagos elemtartalmakra. A termőhely talaja a szántott rétegben 3 % humuszt, 5 % CaCO3-ot és 20 % agyagot tartalmazott. A kísérlet 4Nx4Px4K = 64 kezelést x 2 ismétlést = 128 parcellát foglalt magában. Műtrágyaként 25 %-os pétisót, 18 %- os szuperfoszfátot és 50 %-os kálisót alkalmaztunk. Főbb eredményeink:

A mustár szerveinek tömege átlagosan 2,5-szeresére emelkedett a kontrollhoz viszonyítva a kiegyensúlyozott NxP-trágyázással. Optimális ellátottságot az évenként adott 200 kg/ha N-, valamint a talaj szántott rétegének 140–150 mg/kg ammónium-laktát (AL)-oldható P2O5-, ill. 150–200 mg/kg AL-oldható K2O-tartalma biztosította A magtermés itt 2,4 t/ha-ra emelkedett az abszolút kontrollon mért 1,0 t/ha-ról.

A javuló N-kínálattal nőtt a növényi szervek N %-a, valamint a főbb kationok (K, Ca és Mg) koncentrációja. A P-ellátás javulása serkentette a P, Ca és Mg, ill. gátolta a Zn beépülését a P–Zn antagonizmus nyomán. A K-trágyázás a vegetatív növényi részek K-akkumulációjához, valamint a K–Ca és K–Mg antagonizmus eredményeképpen a Ca- és Mg-koncentrációk mérsékléséhez vezetett.

A tőrózsáskorú hajtás összetétele képes kielégítően tükrözni a növények tápláltsági állapotát és alkalmas diagnosztikai célokra. Optimális összetételt a 4,0–4,5 % N és K, a 0,35–0,45 % P, illetve a 8–12 körüli N/P és K/P, valamint a 0,8–1,2 N/K arány jelentheti. Adataink iránymutatóul szolgálhatnak a szaktanácsadásban, a tavaszi fejtrágyaigény megállapításában.

A mustár trágyaigényes kultúra. Érés kezdetén a föld feletti biomassza 255 kg N, 194 kg Ca, 192 kg K és 26 kg Mg felvételét mutatta. Betakarításig azonban a leszáradó lombbal elvesztette tömegének 20, a felvett foszfornak 16, nitrogénnek 22, kalciumnak 39, magnéziumnak 42, K-készletének 75 %-át. A K 3/4-e az elszáradó lombbal és a kimosódással visszakerült a talajba.

Az 1 t mag + a hozzá tartozó szár és becőtermés fajlagos elemigénye 81 kg N-, 46 kg Ca- (64 kg CaO), 18 kg K- (22 kg K2O), 11 kg P- (25 kg P2O5), 6 kg Mg- (9,4 kg MgO), 2 kg Na-, 2 kg Fe-, 122 g Mn-, 67 g Zn- és 18 g Cumennyiséget jelzett ha-onként. Amennyiben csak a magtermés kerül el a tábláról kombájnoláskor, a 3 t/ha körüli kielégítő magterméssel 135 kg N-, 38–40 kg K2O-, 48 kg P2O5-, 21 kg Ca- és 14 kg Mg-veszteséggel számolhatunk haonként. Kötöttebb és meszes talajon a K-, Ca- és Mg-veszteség elhanyagolhatóvá válik. Ezzel szemben a savanyú és káliumban szegény talajokon a növény bőséges K-, Ca- és Mg-pótlást igényelhet.
Néhány nyugat-dunántúli talaj könnyen oldható nehézfémtartalmának hosszú idő alatti változása
Authors: Szűcs Mihály , Szűcs Mihályné
Published: August 2004

Légszáraz állapotban tárolt talajminták és mintavételi helyeinek 25–27 év elteltével végzett ismételt mintavételezése után vizsgáltuk a Marcal-medencében és a Nyugat-magyarországi-peremvidéken a KCl–EDTA-oldható nehézfémtartalom változását üzemi viszonyok között. A jellemzett időtartam magába foglalja azt az időszakot, amikor viszonylag nagyobb műtrágyaadagokat alkalmaztak az üzemek. A vizsgálat a természetes és a humán eredetű környezeti tényezők együttes, hosszú távú hatása törvényszerűségeinek tanulmányozására irányult.

A vizsgált, döntően barna erdőtalajok által borított régióban a talajok kémhatása az expozíciós idő alatt általában 1 pH-értékkel csökkent, a szervesanyagtartalom viszont nem változott.

Az oldható Cd- és Cr-tartalom a homok mechanikai összetételű területen szignifikánsan csökkent a megfigyelés 26–28 éve alatt, a kötöttebb talajokon nem történt igazolható változás. A homoktalajokon megfigyelt változást a savanyodás hatására fokozódó kilúgozódásnak tulajdonítjuk.

Közlekedési eredetű szennyezést nem tudtunk kimutatni. A szilárd burkolatú közlekedési utak 200 m-es környezetében és az attól nagyobb távolságra mért oldható nehézfémtartalom nem különbözött szignifikánsan.

Nem volt kimutatható összefüggés a talajok oldható nehézfémtartalmának változása és a műtrágyázás hatására változó oldható P- és K-tartalom között.

A vizsgált régióban a talajok oldható Co- és Pb-tartalma szignifikánsan növekedett a megfigyelési idő alatt. A növekedés 70–80 %-ban magyarázható az oldódási és redoxi folyamatok során keletkező könnyen oldható Mn-, Fe- és Altartalommal. Az összefüggésben a meghatározó szerepet a mangán játszotta.

Összességében megállapítható, hogy a vizsgált területen a talajok könnyen oldható nehézfémtartalmának változásait nem külső szennyezés, hanem a talajhasználat által befolyásolt mállási folyamatok és a talajkomponensek közötti átrendeződés okozza.
Néhány nitrogéntartalmú gyomirtó szer fotobomlásának vizsgálata GC-MS módszerrel
Authors: Lányi Katalin , Dinya Zoltán
Published: August 2004

Összehasonlító vizsgálatokat végeztünk 13 gyomirtó szer hatóanyagán azok fotobomlási folyamatainak tanulmányozására. Mivel a spontán alapfolyamatok megfigyelése volt a célunk, nem használtunk adalékanyagokat. Bár a természetben a növényvédő szerek számtalan, a bomlásukat befolyásoló anyaggal találkoznak, a kutatás e fázisában ezeknek a hatásoknak a vizsgálata nem volt célunk. A vizsgálatok alapján felvázoltuk az egyes hatóanyagok bomlási sémáját és a bomlás időbeli lefutását. Megállapítottuk, hogy valamennyi vizsgált vegyület jól mérhető fotoaktivitást mutatott vizsgálati körülményeink között, valamint hogy a legtöbb vegyület bomlásterméke kevésbé környezetidegen, mint az eredeti vegyület volt.

Nem hagyhatjuk azonban figyelmen kívül, hogy természetes körülmények között a talajban számos egyéb folyamat is lejátszódik, a vizsgált vegyületek — elsősorban bázikus jellegű — nitrogénatomján a mikrobiális folyamatok hatására N-oxidáció is bekövetkezhet. Ez egyrészt közvetlenül nitrozovegyületek kialakulásához vezethet, amelyek már magukban is igen toxikusak és karcinogének. A talajban előforduló nitrit- és különösen a nagy mennyiségű nitrátionokkal ezek a nitrozovegyületek tovább is reagálhatnak, és ez a folyamat a fokozottan agresszív karcinogén N-nitrózaminok keletkezéséhez vezethet. Mivel ezek a folyamatok talajtípus függőek, további vizsgálatuk elengedhetetlen.
Identification of Enterococci isolated from cow's milk cheese: comparison of the classical methods and the API 20 strep system
Authors: Fontán María Camino García , Franco I. , Tornadijo M. E. , Carballo J.
Published: August 2004

A comparison of the results obtained using the classical methods with those of the API 20 Strep system was carried out in identifying 24 enterococci strains isolated from San Simón cow's milk cheese, a traditional Spanish variety. The results of both identification systems coincided exactly in 9 strains (37.5% of the strains studied). In one strain the results obtained using the classical methods did not coincide with those using the API 20 Strep method. 3 strains (12.5%) could not be identified using the API 20 Strep system. However, 11 strains (45%), that remained doubtful between both species E. faecalis and E. faecium on the basis of the classical methods, were identified using the API 20 Strep system. The API 20 Strep system does not include some biochemical tests of importance in identifying of foodborne enterococci and could not identify the atypical strains of Enterococcus. Moreover, this system is adapted to the identification of enterococci of clinical origin and their database does not include some species common in foods. However, it could have an application in combination with the classical methods in order to carry out a reasonably rapid and reliable identification of enterococci related to cheese.