bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution and Acute Stressor‐Induced Activation of Corticotrophin‐Releasing Hormone Neurones in the Central Nervous System of Xenopus laevis
Authors: Yao M. , Westphal N. J. , Denver R. J. 
Published: December 2004

AbstractIn mammals, corticotrophin‐releasing hormone (CRH) and related peptides are known to play essential roles in the regulation of neuroendocrine, autonomic and behavioural responses to physical and emotional stress. In nonmammalian species, CRH‐like peptides are hypothesized to play similar neuroendocrine and neurocrine roles. However, there is relatively little detailed information on the distribution of CRH neurones in the central nervous system (CNS) of nonmammalian vertebrates, and there are currently no comparative data on stress‐induced changes in CRH neuronal physiology. We used a specific, affinity‐purified antibody raised against synthetic Xenopus laevis CRH to map the distribution of CRH in the CNS of juvenile South African clawed frogs. We then analysed stress‐induced changes in CRH immunoreactivity (CRH‐ir) throughout the CNS. We found that CRH‐positive cell bodies and fibres are widely distributed throughout the brain and rostral spinal cord of juvenile X. laevis. Strong CRH‐immunoreactovity (ir) was found in cell bodies and fibres in the anterior preoptic area (POA, an area homologous to the mammalian paraventricular nucleus) and the external zone of the median eminence. Specific CRH‐ir cell bodies and fibres were also identified in the septum, pallium and striatum in the telencephalon; the amygdala, bed nucleus of the stria terminalis and various hypothalamic and thalamic nuclei in the diencephalon; the tectum, torus semicircularis and tegmental nuclei of the mesencephalon; the cerebellum and locus coeruleus in the rhombencephalon; and the ventral horn of the rostral spinal cord. To determine if exposure to an acute physical stressor alters CRH neuronal physiology, we exposed juvenile frogs to shaking/handling and conducted morphometric analysis. Plasma corticosterone was significantly elevated by 30 min after exposure to the stressor and continued to increase up to 6 h. Morphometric analysis of CRH‐ir after 4 h of stress showed a significant increase in CRH‐ir in parvocellular neurones of the anterior preoptic area, the medial amygdala and the bed nucleus of the stria terminalis, but not in other brain regions. The stress‐induced increase in CRH‐ir in the POA was associated with increased Fos‐like immunoreactivity (Fos‐LI), and confocal microscopy showed that CRH‐ir colocalized with Fos‐LI in a subset of Fos‐LI‐positive neurones. Our results support the view that the basic pattern of CNS CRH expression arose early in vertebrate evolution and lend further support to earlier studies suggesting that amphibians may be a transitional species for descending CRH‐ergic pathways. Furthermore, CRH neurones in the frog brain exhibit changes in response to a physical stressor that parallel those seen in mammals, and thus are likely to play an active role in mediating neuroendocrine, behavioural and autonomic stress responses.
Inter‐Relationships Between the Secretory Dynamics of Thyrotrophin‐Releasing Hormone, Thyrotrophin and Prolactin in Periovulatory Mares: Effect of Hypothyroidism
Authors: Alexander S. L. , Irvine C. H. G. , Evans M. J. 
Published: December 2004

AbstractWe used our nonsurgical technique for collecting pituitary venous blood to relate the dynamics of thyrotrophin‐releasing hormone (TRH) secretion to the secretion patterns of both prolactin and thyrotrophin in periovulatory mares, either euthyroid (n = 5) or made hypothyroid by treatment with propyl‐thiouracil (n = 5). Pituitary venous blood was collected continuously and divided into 1‐min aliquots for 4 h. To test the effect of dopamine on the relationship between secretion patterns, sulpiride, a selective D2 receptor antagonist, was given i.m. after 2 h of sampling. Thorough testing of the model and blood collection procedure revealed no sites of TRH loss. Hypothyroidism increased the mean secretion rates of TRH (P = 0.04) and thyrotrophin (P < 0.0001) but not prolactin. Sulpiride increased prolactin secretion rates in hypothyroid (P < 0.0001) and control (P = 0.007) mares, but did not alter TRH or thyrotrophin secretion rates. In both groups of mares, all three hormones were secreted episodically but not rhythmically. In both groups, the secretion pattern of TRH was almost always significantly related to that of thyrotrophin, as assessed by cross correlation and cross approximate entropy (ApEn) analysis. However, the degree of linear correlation was weak, with only 14% (hypothyroid) or 8% (controls) of the variation in thyrotrophin secretion rates attributable to TRH. Prolactin and TRH secretion patterns before sulpiride were coupled on cross ApEn analysis in both groups, and the minute‐to‐minute secretion rates of the two hormones were correlated in four hypothyroid and three euthyroid mares. Overall, the small, but significant, degree of association between TRH and prolactin was similar to that between TRH and thyrotrophin. In hypothyroid mares, sulpiride increased (P = 0.02) the synchrony between TRH and prolactin patterns. We conclude that in horses: (i) little TRH degradation occurs during passage through the pituitary or in blood after 1 h at 37 °C; (ii) TRH is not the major factor controlling minute‐to‐minute fluctuations in either thyrotrophin or prolactin; and (iii) reducing two strongly inhibitory inputs (i.e. dopamine and thyroid hormones) may magnify the stimulatory effect of TRH on prolactin secretion.
Concurrent interactions of heme and FLU with Glu tRNA reductase (HEMA1), the target of metabolic feedback inhibition of tetrapyrrole biosynthesis, in dark‐ and light‐grown Arabidopsis plants
Authors: Goslings David , Meskauskiene Rasa , Kim Chanhong , Lee Keun Pyo , Nater Mena , Apel Klaus 
Published: December 2004

SummaryThe regulation of tetrapyrrole biosynthesis in higher plants has been attributed to metabolic feedback inhibition of Glu tRNA reductase by heme. Recently, another negative regulator of tetrapyrrole biosynthesis has been discovered, the FLU protein. During an extensive second site screen of mutagenized flu seedlings a suppressor of flu, ulf3, was identified that is allelic to hy1 and encodes a heme oxygenase. Increased levels of heme in the hy1 mutant have been implicated with inhibiting Glu tRNA reductase and suppressing the synthesis of δ‐aminolevulinic acid (ALA) and Pchlide accumulation. When combined with hy1 or ulf3 upregulation of ALA synthesis and overaccumulation of protochlorophyllide in the flu mutants were severely suppressed supporting the notion that heme antagonizes the effect of the flu mutation by inhibiting Glu tRNA reductase independently of FLU. The coiled‐coil domain at the C‐terminal end of Glu tRNA reductase interacts with FLU, whereas the N‐terminal site of Glu tRNA reductase that is necessary for the inhibition of the enzyme by heme is not required for this interaction. The interaction with FLU is specific for the Glu tRNA reductase encoded by HEMA1 that is expressed in photosynthetically active tissues. FLU seems to be part of a second regulatory circuit that controls chlorophyll biosynthesis by interacting directly with Glu tRNA reductase not only in etiolated seedlings but also in light‐adapted green plants.
The tomato carotenoid cleavage dioxygenase 1 genes contribute to the formation of the flavor volatiles β‐ionone, pseudoionone, and geranylacetone
Authors: Simkin Andrew J. , Schwartz Steven H. , Auldridge Michele , Taylor Mark G. , Klee Harry J. 
Published: December 2004

SummaryVolatile terpenoid compounds, potentially derived from carotenoids, are important components of flavor and aroma in many fruits, vegetables and ornamentals. Despite their importance, little is known about the enzymes that generate these volatiles. The tomato genome contains two closely related genes potentially encoding carotenoid cleavage dioxygenases, LeCCD1A and LeCCD1B. A quantitative reverse transcriptase‐polymerase chain reaction analysis revealed that one of these two genes, LeCCD1B, is highly expressed in ripening fruit (4 days post‐breaker), where it constitutes 0.11% of total RNA. Unlike the related neoxanthin cleavage dioxygenases, import assays using pea chloroplasts showed that the LeCCD1 proteins are not plastid‐localized. The biochemical functions of the LeCCD1 proteins were determined by bacterial expression and in vitro assays, where it was shown that they symmetrically cleave multiple carotenoid substrates at the 9,10 (9′,10′) positions to produce a C14 dialdehyde and two C13 cyclohexones that vary depending on the substrate. The potential roles of the LeCCD1 genes in vivo were assessed in transgenic tomato plants constitutively expressing the LeCCD1B gene in reverse orientation. This over‐expression of the antisense transcript led to 87–93% reductions in mRNA levels of both LeCCD1A and LeCCD1B in the leaves and fruits of selected lines. Transgenic plants exhibited no obvious morphological alterations. High‐performance liquid chromatography analysis showed no significant modification in the carotenoid content of fruit tissue. However, volatile analysis showed a ≥50% decrease in β‐ionone (a β‐carotene‐derived C13 cyclohexone) and a ≥60% decrease in geranylacetone (a C13 acyclic product likely derived from a lycopene precursor) in selected lines, implicating the LeCCD1 genes in the formation of these important flavor volatiles in vivo.
The ubiquitin ligase XBAT32 regulates lateral root development in Arabidopsis
Authors: Nodzon Lisa A. , Xu Wei‐Hui , Wang Yongsheng , Pi Li‐Ya , Chakrabarty Pranjib K. , Song Wen‐Yuan 
Published: December 2004

SummaryUbiquitin‐mediated protein modification plays a key role in many cellular signal transduction pathways. The Arabidopsis gene XBAT32 encodes a protein containing an ankyrin repeat domain at the N‐terminal half and a RING finger motif. The XBAT32 protein is capable of ubiquitinating itself. Mutation in XBAT32 causes a number of phenotypes including severe defects in lateral root production and in the expression of the cell division marker CYCB1;1::GUS. The XBAT32 gene is expressed abundantly in the vascular system of the primary root, but not in newly formed lateral root primordia. Treatment with auxin increases the expression of XBAT32 in the primary root and partially rescues the lateral root defect in xbat32‐1 mutant plants. Thus, XBAT32 is a novel ubiquitin ligase required for lateral root initiation.
Overexpression of tomato LeAGP‐1 arabinogalactan‐protein promotes lateral branching and hampers reproductive development
Authors: Sun Wenxian , Kieliszewski Marcia J. , Showalter Allan M. 
Published: December 2004

SummaryLeAGP‐1 is a glycosylphosphatidylinositol (GPI)‐anchored arabinogalactan‐protein (AGP) in tomato (Lycopersicon esculentum). Patterns of mRNA expression and protein localization for LeAGP‐1 indicate that it likely functions in certain aspects of plant growth and development. To elucidate LeAGP‐1 function(s), transgenic tomato plants expressing enhanced green fluorescent protein (GFP) fused to LeAGP‐1 [GFP‐LeAGP‐1] or two LeAGP‐1 variants, one lacking the C‐terminal GPI‐anchor domain [GFP‐LeAGP‐1ΔC] and the other lacking the lysine‐rich domain [GFP‐LeAGP‐1ΔK], under the control of the CaMV35S promoter were produced using Agrobacterium‐mediated transformation. Transgenic T0 and T1 lines with high levels of both GFP‐LeAGP‐1 mRNA and protein: (i) were significantly shorter; (ii) were highly branched; (iii) produced more flower buds, but most of these flowers did not mature, resulting in less fruit production; and (iv) produced seeds that were significantly smaller than normal seeds. Overexpression of LeAGP‐1ΔK had a similar or even more pronounced effect on plant vegetative and reproductive growth, while the effect of LeAGP‐1ΔC overexpression on plant reproduction was minimal. These results indicate that the GPI anchor is critical for LeAGP‐1 function. As the phenotype of GFP‐LeAGP‐1 overexpressing transgenic plants is similar to that of cytokinin‐overproducing plants, mRNA expression patterns of LeAGP‐1 under different hormone treatments were examined. Cytokinins upregulated LeAGP‐1 mRNA expression, while auxins and ABA inhibited LeAGP‐1 mRNA expression. Based on these results, GPI‐anchored LeAGP‐1 most likely functions in plant growth and development in concert with auxin/cytokinin signaling.
AtMYB32 is required for normal pollen development in Arabidopsis thaliana
Authors: Preston Jeremy , Wheeler Janet , Heazlewood Joshua , Li Song Feng , Parish Roger W. 
Published: December 2004

Summary AtMYB32 gene is a member of the R2R3 MYB gene family coding for transcription factors in Arabidopsis thaliana. Its expression pattern was analysed using Northern blotting, in situ hybridization and promoter‐GUS fusions. AtMYB32 is expressed in many tissues, but most strongly in the anther tapetum, stigma papillae and lateral root primordia. AtMYB32‐GUS was induced in leaves and stems following wounding, and in root primordia by auxin. T‐DNA insertion populations were screened and two insertion mutants were identified, both of which were partially male sterile, more than 50% of the pollen grains being distorted in shape and lacking cytoplasm. AtMYB4 is closely related to AtMYB32 and represses the CINNAMATE 4‐HYDROXYLASE gene. Distorted pollen grains were produced in both AtMYB4 insertion mutant and overexpression lines. In an AtMYB32 insertion mutant, the transcript levels of the DIHYDROFLAVONOL 4‐REDUCTASE and ANTHOCYANIDIN SYNTHASE genes decreased while the level of the CAFFEIC ACID 0‐METHYLTRANSFERASE transcript increased. Change in the levels of AtMYB32 and AtMYB4 expression may influence pollen development by changing the flux along the phenylpropanoid pathways, affecting the composition of the pollen wall.
Amplification of proopiomelanocortin mRNA in canine skin: preliminary results
Authors: KIDNEY CAROLYN M. , MACDONALD JOHN M. , ANGARANO DONNA W. , INSALACO THOMAS A. , KEMPAINNEN ROBERT J. , SARTIN JAMES L. 
Published: December 2004

Abstract Skin and pituitary specimens were obtained from a normal chow‐chow cross‐bred dog. Total messenger RNA (mRNA) was extracted, reversed transcribed and the proopiomelanocortin (POMC) mRNA was amplified by polymerase chain reaction using canine specific primers. The expected 391 bp amplification product was detected in both canine skin and pituitary samples. Sequencing of this product showed 100% homology to the GenBank sequence for canine PMOC cDNA, and confirmed its remarkable homology to sequences of human, pigtailed macaque, mink, pig, mouse, rat and cow POMC. These preliminary results suggest that transcription of POMC mRNA occurs in canine skin. The nature of resident or nonresident cells transcribing the POMC gene in canine skin remains unknown at this time.
Evaluation of adrenal function in small‐breed dogs receiving otic glucocorticoids
Authors: GHUBASH R. , MARSELLA R. , KUNKLE G. 
Published: December 2004

Abstract The objectives of this study were to evaluate adrenal function after otic glucocorticoid [Tresaderm® (dexamethasone) and Otomax® (betamethasone)] therapy in small‐breed dogs without evidence of otitis and to evaluate the length of time needed for resolution of adrenal suppression after discontinuation of treatment. Fourteen clinically healthy, privately owned, small‐breed dogs with normal ears and normal adrenocorticotropin (ACTH) stimulation tests were assigned to one of two treatment groups, receiving one of the medications at the manufacturer's recommended dosage twice daily for 2 weeks. All of the dogs in the betamethasone treatment group had normal ACTH stimulation tests after 2 weeks of treatment. In contrast, 5/7 (71.43%) in the dexamethasone group, had suppressed adrenocortical responses to exogenous ACTH. Three of these five dogs (42%) returned to normal values 1 week after ceasing the medication and two (28.57%) returned to normal values 2 weeks after ceasing the medication. In conclusion, it appears that adrenal function can be suppressed for up to 2 weeks in dogs receiving otic dexamethasone. A follow‐up study repeating this work in dogs with inflamed ears is needed before further clinical recommendations can be made.
Quantification of Blo t 5 in mite and dust extracts by two‐site ELISA
Authors: Yi F. C. , Lee B. W. , Cheong N. , Chua K. Y. 
Published: December 2004

Background:  Blomia tropicalis is an important mite species in the tropical and sub‐tropical regions of the world. Blo t 5 is the major allergen with up to 70% sensitization rates in B. tropicalis allergic populations.Methods:  Mice were immunized intramuscularly with naked plasmid DNA encoding Blo t 5 gene with in vivo electroporation. Blo t 5 monoclonal antibodies were generated using methylcellulose‐based hybridoma kit. Monoclonal antibody (mAb) 4A7 was characterized by two‐dimensional electrophoresis immunoblotting. A specific quantitative two‐site enzyme‐linked immunosorbent assay (ELISA) was developed with mAb 4A7 and guinea pigs Blo t 5 polyclonal antibody as capture and detection antibodies, respectively. This system was tested with Blo t 5 in crude extracts and dust samples.Results:  A high‐affinity mAb 4A7 recognizing several isoforms of Blo t 5 has been generated. Monoclonal antibody 4A7 is useful for immunoblotting and two‐site ELISA. The two‐site ELISA developed has a high sensitivity, with a detection limit of 10 pg/ml. The assay is species‐specific and recognized the same epitopes on both native and recombinant Blo t 5. The assay developed is able to detect Blo t 5 in commercial diagnostic and therapeutic B. tropicalis extract. Blo t 5 quantification in dust samples showed that Blo t 5 is present in a high quantity in Singapore dust.Conclusions:  A highly sensitive and specific two‐site ELISA has been developed. The assay system developed is useful for the quantification of Blo t 5 in mite and environmental dust extracts.
Organization of secondary lymphoid tissue and local IgE formation to Staphylococcus aureus enterotoxins in nasal polyp tissue
Authors: Gevaert P. , Holtappels G. , Johansson S. G. O. , Cuvelier C. , van Cauwenberge P. , Bachert C. 
Published: December 2004

Background:  Bilateral nasal polyposis (NP) is characterized by high concentrations of IgE in NP tissue, which show no relation to the atopic status. We aimed to study the relationship between systemic and local IgE formation, nasal carriage of Staphylococcus aureus and nasal polyposis.Methods:  In serum and nasal tissue homogenates from 24 NP patients and 12 controls, we determined concentrations of total IgE and IgE antibodies to inhalant allergens and S. aureus enterotoxins (SAEs; A,B,C,D,E,TSST) by ImmunoCAP. Tissue cryosections were stained for CD3, CD20, CD38, CD23, FcεRI, IgE and SEA/SEB.Results:  We demonstrated a higher incidence of S. aureus colonization (17/24) and IgE antibodies to SAEs in NP tissue (12/24) compared with controls (3/12 and 0/12, respectively). Total IgE and IgE antibodies in serum and NP tissue were dissociated because of local polyclonal IgE formation in NP tissue. Staining of NP tissue revealed follicular structures characterized by B and T cells, and lymphoid accumulations with diffuse plasma cell infiltration.Conclusions:  We demonstrated the organization of secondary lymphoid tissue in polyp tissue and a polyclonal hyper‐immunoglobulinemia E associated with the presence of IgE antibodies to SAEs, colonization with S. aureus, and tissue eosinophilia in a relevant subgroup of polyp patients.
Bone disease in primary biliary cirrhosis: Lack of association with distal renal tubular acidosis
Authors: FARIAS ALBERTO Q , GONÇALVES LUCIANA L , CANÇADO EDUARDO LR , SEGURO ANTONIO C , CAMPOS SILVIA B , ABRANTES‐LEMOS CLARICE P , CARRILHO FLAIR J 
Published: December 2004

AbstractBackground and Aims: Primary biliary cirrhosis (PBC) might be complicated by osteoporosis, whose etiology remains unknown but seems to be multifactorial. Prevalence rates of 30% to 60% for distal renal tubular acidosis (DRTA) have been reported in PBC patients, generally as incomplete DRTA. Although it is undisputed that a reduced bone mineral density (BMD) is the expected outcome among patients who have been suffering from longstanding chronic metabolic acidosis, it is unclear if incomplete DRTA is also associated with metabolic bone disease in PBC patients. The present study was undertaken to compare the BMD of PBC patients with and without DRTA.Methods: The BMD of 23 PBC patients (11 with DRTA and 12 without), all with normal clearance of creatinine, was assessed by dual energy radiograph absorptiometry. The diagnosis of DRTA was made if the urine pH was above 5.4 in all samples after the oral acid overload, showing tubular inability to acidify urine in the presence of test‐induced systemic metabolic acidosis.Results: Densitometric signs of osteoporosis were found in 82% of DRTA cases and in 83% of patients without DRTA (difference not significant). There were no significant differences in BMD measurement, T and Z scores of patients with and without DRTA.Conclusions: The present study could not support a correlation between the presence of DRTA and the bone loss observed in PBC patients.
Physiological and morphological variation of Gremmeniella abietina from Spain
Authors: Santamaría O. , Pajares J. A. , Diez J. J. 
Published: December 2004

Summary Gremmeniella abietina isolated from Pinus halepensis in Spain was characterized based on disease symptoms and conidia morphology. The disease symptoms, which became more evident in the spring, included drying up of needles and branches with some distortion of terminal twigs, resulting in dieback and sometimes to death of trees of all sizes. Variation in conidia size and growth rate was investigated between 15 isolates from Spain, and the conidia morphology was compared with four isolates from Finland, four from Switzerland and three from the US. Great variation occurred between Spanish isolates both in growth rates and in conidia size. The growth rates of the isolates were greatest on malt agar amended with pine needle extract and at 15°C. The length and the width of the conidia of the isolates from Spain ranged between 10.7–44.8 and 1.5–4.4 μm, and most of them had three septa. The results suggest that the isolates from Spain do not belong to the Alpine biotype, and the disease symptoms caused by these isolates resembled those of the European biotype.