bluuebunny/crossref_metadata_2025 huggingface dataset:
First Report of Goss's Bacterial Wilt and Leaf Blight on Corn Caused by Clavibacter michiganensis subsp. nebraskensis in Indiana
Authors: Ruhl G. , Wise K. , Creswell T. , Leonberger A. , Speers C.
Published: July 2009

In August of 2008, leaves of hybrid corn (Zea mays L.) and popcorn from Pulaski and Jasper counties in northwest Indiana were submitted to the Purdue Plant and Pest Diagnostic Lab with symptoms characteristic of a bacterial disease. Symptomatic leaves had large, tan-to-gray necrotic lesions with dark freckling present within the lesions. Shiny bacterial exudate was present on the surface of many of the lesions. Microscopic observation revealed no fungal structures within the lesions, and bacterial streaming was observed from the cut edge of symptomatic tissue under ×100 magnification with phase contrast. A commercially available ELISA test (Agdia Inc., Elkhart, IN) determined that samples were negative for Pantoea stewartii, the causal agent of Stewart's bacterial leaf blight and wilt. A bacterial suspension was prepared from symptomatic tissue and streaked onto King's B medium and subcultured on semiselective CNS medium (1,2). Axenic, peach-colored colonies present on the CNS medium tested gram positive with a KOH test. Analysis of fatty acid methyl esters (MIDI Inc, Newark, DE) indicated that the strain was very similar (0.611) to Clavibacter michiganensis. Amplification of the 500-bp 16S rRNA region of the bacterial gene and subsequent BLAST alignments of the resulting sequence indicated a 99% match for C. michiganensis subsp. nebraskensis (GenBank Accession Nos. AM410697 and U09763; D16S2 gene bacterial library, version 2.10; MIDI Inc,). Koch's postulates were used to confirm pathogenicity of the isolated bacteria on corn inbred B73. Eighteen plants were mechanically inoculated at growth stage V1 to V2 with a bacterial suspension of approximately 1 × 108 CFU/ml prepared from cultures grown on CNS for 10 days at 28°C (2). Inoculum was rubbed onto leaves dusted with Carborundum and 0.1 ml of the bacterial suspension was injected into stems with a hypodermic needle. Nine control plants were inoculated with sterile water. Plants were kept at greenhouse conditions (24°C) with supplemental 400W high-pressure sodium light. Within 5 to 8 days, leaves and stems of all 18 inoculated plants developed water-soaked, necrotic lesions. No symptoms were observed in control plants. Bacteria were reisolated from symptomatic plants on CNS medium as described above, and gram-positive colonies were obtained. Reisolated strains were identical to C. michiganensis subsp. nebraskensis by D16S2 DNA sequence analysis, confirming the causal agent of the disease. Disease incidence in affected fields ranged from 20 to 60% and significant yield loss was reported. This confirmation is of regulatory importance because of potential export restrictions of Indiana-grown seed corn and popcorn to select countries. To our knowledge, this is the first report of Goss's bacterial wilt and leaf blight on corn in Indiana.

References: (1) D. C. Gross and A. K. Vidaver. Phytopathology 69:82, 1979. (2) L. M. Shepherd. M.S. thesis. Iowa State University. Ames, 1999.
Divergence time of the two regional medaka populations in Japan as a new time scale for comparative genomics of vertebrates
Authors: Setiamarga Davin H. E. , Miya Masaki , Yamanoue Yusuke , Azuma Yoichiro , Inoue Jun G. , Ishiguro Naoya B. , Mabuchi Kohji , Nishida Mutsumi
Published: July 2009

The southern and northern Japanese populations of the medaka fish provide useful tools to gain insights into the comparative genomics and speciation of vertebrates, because they can breed to produce healthy and fertile offspring despite their highly divergent genetic backgrounds compared with those of human–chimpanzee. Comparative genomics analysis has suggested that such large genetic differences between the two populations are caused by higher molecular evolutionary rates among the medakas than those of the hominids. The argument, however, was based on the assumption that the two Japanese populations diverged approximately at the same time (4.0–4.7 Myr ago) as the human–chimpanzee lineage (5.0–6.0 Myr ago). This can be misleading, because the divergence time of the two populations was calculated based on estimated, extremely higher molecular evolutionary rates of other fishes with an implicit assumption of a global molecular clock. Here we show that our estimate, based on a Bayesian relaxed molecular-clock analysis of whole mitogenome sequences from 72 ray-finned fishes (including 14 medakas), is about four times older than that of the previous study (18 Myr). This remarkably older estimate can be reconciled with the vicariant events of the Japanese archipelago, and the resulting rates of molecular evolution are almost identical between the medaka and hominid lineages. Our results further highlight the fact that reproductive isolation may not evolve despite a long period of geographical isolation.
Melanocyte pigmentation stiffens murine cardiac tricuspid valve leaflet
Authors: Balani Kantesh , Brito Flavia C. , Kos Lidia , Agarwal Arvind
Published: July 2009

Pigmentation of murine cardiac tricuspid valve leaflet is associated with melanocyte concentration, which affects its stiffness. Owing to its biological and viscoelastic nature, estimation of the
in situ
stiffness measurement becomes a challenging task. Therefore, quasi-static and nanodynamic mechanical analysis of the leaflets of the mouse tricuspid valve is performed in the current work. The mechanical properties along the leaflet vary with the degree of pigmentation. Pigmented regions of the valve leaflet that contain melanocytes displayed higher storage modulus (7–10 GPa) than non-pigmented areas (2.5–4 GPa). These results suggest that the presence of melanocytes affects the viscoelastic properties of the mouse atrioventricular valves and are important for their proper functioning in the organism.
Odour intensity learning in fruit flies
Authors: Yarali Ayse , Ehser Sabrina , Hapil Fatma Zehra , Huang Ju , Gerber Bertram
Published: July 2009

Animals' behaviour towards odours depends on both odour quality and odour intensity. While neuronal coding of odour quality is fairly well studied, how odour intensity is treated by olfactory systems is less clear. Here we study odour intensity processing at the behavioural level, using the fruit flyDrosophila melanogaster. We trained flies by pairing a MEDIUM intensity of an odour with electric shock, and then, at a following test phase, measured flies' conditioned avoidance of either this previously trained MEDIUM intensity or a LOWer or a HIGHer intensity. With respect to 3-octanol,n-amylacetate and 4-methylcyclohexanol, we found that conditioned avoidance is strongest when training and test intensities match, speaking for intensity-specific memories. With respect to a fourth odour, benzaldehyde, on the other hand, we found no such intensity specificity. These results form the basis for further studies of odour intensity processing at the behavioural, neuronal and molecular level.
A new Lower Cretaceous bird from China and tooth reduction in early avian evolution
Authors: Zhou Zhonghe , Li Fucheng Zhang Zhiheng
Published: July 2009

A new avian genus and species,
Zhongjianornis yangi
gen. et sp. nov., is reported from the Lower Cretaceous lacustrine deposits of the Jiufotang Formation in Liaoning, northeast China. The new taxon is characterized by possessing the following combination of features: upper and lower jaws toothless, snout pointed, humerus with large and robust deltopectoral crest, second phalanx of the major manual digit longer than the first phalanx, unguals of the alular and major digits of similar length and significantly shorter than the corresponding penultimate phalanges, tibiotarsus slender and more than twice the length of the tarsometatarsus, and metatarsal IV longer than the other metatarsals. Phylogenetic analysis indicates that
Zhongjianornis
is phylogenetically basal to
Confuciusornis
and the dominant Mesozoic avian groups, Enantiornithes and Ornithurae, and therefore provides significant new information regarding the diversification of birds in the Early Cretaceous. It also represents the most basal bird that completely lacks teeth, suggesting that tooth loss was more common than expected in early avian evolution and that the avian beak appeared independently in several avian lineages, most probably as a response to selective pressure for weight reduction. Finally, the presence of a significantly enlarged humeral deltopectoral crest suggests that
Zhongjianornis
shares with other basal birds such as
Jeholornis
,
Sapeornis
and
Confuciusornis
a distinctive mode of adaptation for flight contrasting with that seen in more advanced birds, which instead possess an elongated sternum and a prominent keel.
Overexpressing AtPAP15 Enhances Phosphorus Efficiency in Soybean
Authors: Wang Xiurong , Wang Yingxiang , Tian Jiang , Lim Boon Leong , Yan Xiaolong , Liao Hong
Published: July 2009

Low phosphorus (P) availability is a major constraint to crop growth and production, including soybean (Glycine max), on a global scale. However, 50% to 80% of the total P in agricultural soils exists as organic phosphate, which is unavailable to plants unless hydrolyzed to release inorganic phosphate. One strategy for improving crop P nutrition is the enhanced activity of acid phosphatases (APases) to obtain or remobilize inorganic phosphate from organic P sources. In this study, we overexpressed an Arabidopsis (Arabidopsis thaliana) purple APase gene (AtPAP15) containing a carrot (Daucus carota) extracellular targeting peptide in soybean hairy roots and found that the APase activity was increased by 1.5-fold in transgenic hairy roots. We subsequently transformed soybean plants with AtPAP15 and studied three homozygous overexpression lines of AtPAP15. The three transgenic lines exhibited significantly improved P efficiency with 117.8%, 56.5%, and 57.8% increases in plant dry weight, and 90.1%, 18.2%, and 62.6% increases in plant P content, respectively, as compared with wild-type plants grown on sand culture containing phytate as the sole P source. The transgenic soybean lines also exhibited a significant level of APase and phytase activity in leaves and root exudates, respectively. Furthermore, the transgenic lines exhibited improved yields when grown on acid soils, with 35.9%, 41.0%, and 59.0% increases in pod number per plant, and 46.0%, 48.3%, and 66.7% increases in seed number per plant. Taken together, to our knowledge, our study is the first report on the improvement of P efficiency in soybean through constitutive expression of a plant APase gene. These findings could have significant implications for improving crop yield on soils low in available P, which is a serious agricultural limitation worldwide.
Structural and Enzymatic Characterization of Os3BGlu6, a Rice β-Glucosidase Hydrolyzing Hydrophobic Glycosides and (1→3)- and (1→2)-Linked Disaccharides
Authors: Seshadri Supriya , Akiyama Takashi , Opassiri Rodjana , Kuaprasert Buabarn , Cairns James Ketudat
Published: July 2009

Glycoside hydrolase family 1 (GH1) β-glucosidases play roles in many processes in plants, such as chemical defense, alkaloid metabolism, hydrolysis of cell wall-derived oligosaccharides, phytohormone regulation, and lignification. However, the functions of most of the 34 GH1 gene products in rice (Oryza sativa) are unknown. Os3BGlu6, a rice β-glucosidase representing a previously uncharacterized phylogenetic cluster of GH1, was produced in recombinant Escherichia coli. Os3BGlu6 hydrolyzed p-nitrophenyl (pNP)-β-d-fucoside (k  cat  /K  m = 67 mm  −1 s−1), pNP-β-d-glucoside (k  cat  /K  m = 6.2 mm  −1 s−1), and pNP-β-d-galactoside (k  cat  /K  m = 1.6 mm  −1s−1) efficiently but had little activity toward other pNP glycosides. It also had high activity toward n-octyl-β-d-glucoside and β-(1→3)- and β-(1→2)-linked disaccharides and was able to hydrolyze apigenin β-glucoside and several other natural glycosides. Crystal structures of Os3BGlu6 and its complexes with a covalent intermediate, 2-deoxy-2-fluoroglucoside, and a nonhydrolyzable substrate analog, n-octyl-β-d-thioglucopyranoside, were solved at 1.83, 1.81, and 1.80 Å resolution, respectively. The position of the covalently trapped 2-F-glucosyl residue in the enzyme was similar to that in a 2-F-glucosyl intermediate complex of Os3BGlu7 (rice BGlu1). The side chain of methionine-251 in the mouth of the active site appeared to block the binding of extended β-(1→4)-linked oligosaccharides and interact with the hydrophobic aglycone of n-octyl-β-d-thioglucopyranoside. This correlates with the preference of Os3BGlu6 for short oligosaccharides and hydrophobic glycosides.
A Phosphofructokinase B-Type Carbohydrate Kinase Family Protein, NARA5, for Massive Expressions of Plastid-Encoded Photosynthetic Genes in Arabidopsis
Authors: Ogawa Taro , Nishimura Kenji , Aoki Takehiko , Takase Hisabumi , Tomizawa Ken-Ichi , Ashida Hiroki , Yokota Akiho
Published: July 2009

To date, there have been no reports on screening for mutants defective in the massive accumulation of Rubisco in higher plants. Here, we describe a screening method based on the toxic accumulation of ammonia in the presence of methionine sulfoximine, a specific inhibitor of glutamine synthetase, during photorespiration initiated by the oxygenase reaction of Rubisco in Arabidopsis (Arabidopsis thaliana). Five recessive mutants with decreased amounts of Rubisco were identified and designated as nara mutants, as they contained a mutation in genes necessary for the achievement of Rubisco accumulation. The nara5-1 mutant showed markedly lower levels of plastid-encoded photosynthetic proteins, including Rubisco. Map-based cloning revealed that NARA5 encoded a chloroplast phosphofructokinase B-type carbohydrate kinase family protein of unknown function. The NARA5 protein fused to green fluorescent protein localized in chloroplasts. We conducted expression analyses of photosynthetic genes during light-induced greening of etiolated seedlings of nara5-1 and the T-DNA insertion mutant, nara5-2. Our results strongly suggest that NARA5 is indispensable for hyperexpression of photosynthetic genes encoded in the plastid genome, particularly rbcL.
Modifications of the Cardiovascular System With Aging
Authors: Alberto U. Ferrari
Published: July 2009

Aging is accompanied by significant cardiovascular modifications, both structural and functional. A slight degree of left ventricular hypertrophy develops, while the resting heart rate and early filling rate are somewhat decreased. In contrast, end‐diastolic and end‐systolic dimensions, stroke volume, and ejection fraction are largely unchanged. The effort tachycardic and inotropic responses are clearly attenuated, whereas the concomitant increase in end‐diastolic diameter is enhanced. Large arterial conduits become less distensible and somewhat hypertrophic. Total blood volume is reduced, whereas total peripheral resistance is moderately increased. Neurohumoral systems relevant to cardiovascular regulation are nonuniformly affected by aging: the sympathetic nervous system is overactive and the circulating levels of vasopressin and atrial natriuretic factor are enhanced, while the activity of the renin‐angiotensin system is blunted. Elderly individuals have altered cardiovascular homeostasis, with a typical propensity to postural and postprandial hypotension. “Spontaneous” blood pressure variability is increased, whereas heart rate variability is diminished. Vagally mediated chronotropic responses, including those dependent on baroreflex modulation, are attenuated, although end‐organ (cardiac) parasympathetic responsiveness is exaggerated. Arterial baroreceptor control of blood pressure is largely preserved in advanced age, whereas cardiopulmonary‐mediated reflex responses are definitely impaired.
Extracellular NM23 protein promotes the growth and survival of primary cultured human acute myelogenous leukemia cells
Authors: Okabe‐Kado Junko , Kasukabe Takashi , Honma Yoshio , Kobayashi Hirofumi , Maseki Nobuo , Kaneko Yasuhiko
Published: July 2009

An elevated serum level of NM23‐H1 protein is found in acute myelogenous leukemia (AML), and predicts a poor treatment outcome in AML patients. To investigate the potential pathological link between the elevated serum level of this protein and poor prognosis, we examined the extracellular effects of recombinant NM23‐H1 protein on the in vitro growth and survival of primary cultured AML cells at concentrations equivalent to the levels found in the serum of AML patients. Extracellular NM23‐H1 protein promoted the in vitro growth and survival of AML cells and this activity was associated with the cytokine production and activation of the MAPK and signal transducers and activators of transcription signaling pathways. Inhibitors specific to MAPK signaling pathways inhibited the growth‐ and survival‐promoting activity of NM23‐H1. These findings indicate the novel biological action of extracellular NM23‐H1 and its association with poor prognosis, and suggest an important role for extracellular NM23‐H1 in the malignant progression of leukemia and a potential therapeutic target for these malignancies. (Cancer Sci 2009; 100: 1885–1894)
Impact of a Bereavement and Donation Service incorporating mandatory ‘required referral’ on organ donation rates: a model for the implementation of the Organ Donation Taskforce’s recommendations
Authors: Murphy F. , Cochran D. , Thornton S.
Published: July 2009

In 2008 the Organ Donation Taskforce published its recommendations for increasing organ donation in the UK by 50% over 5 years. Bolton NHS Trust has addressed the problem of low rates of organ donation by amalgamating Bereavement and Donation Services and introducing a trigger to refer automatically all potential organ donors to the regional transplant donor co‐ordinators. We audited the ability of the new service to deliver the aims and recommendations of the Organ Donation Taskforce. Following the changes in service provision the number of tissue donors rose from six in 2002 to 246 in 2007. In the same period solid organ donation rates remained unchanged. The introduction of an automatic trigger for referral of potential donors in 2007 resulted in 31 referrals and 11 successful multi‐organ donors. The current service exceeds the aims of the Taskforce and offers the potential to meet UK organ donation targets without resorting to an ‘opt out’ system of presumed consent.
Effects of different doses of remifentanil on the end‐tidal concentration of sevoflurane required for tracheal intubation in children
Authors: He L. , Wang X. , Zhang X‐F. , Tang S‐R.
Published: July 2009

We investigated the effects of different doses of remifentanil on the end‐tidal concentration of sevoflurane required for tracheal intubation in children without the use of neuromuscular blocking drugs. One hundred and thirty paediatric patients, aged 3–8 years, were randomly allocated to receive no remifentanil (group control) or remifentanil 0.1 μg.kg−1.min−1 (group remi0.1), 0.2 μg.kg−1.min−1 (group remi0.2), 0.3 μg.kg−1.min−1 (group remi0.3). All patients were anaesthetised using 5% sevoflurane. After loss of eyelash reflex, remifentanil 1 μg.kg−1 was injected over 1 min followed by an appropriate group‐dependent infusion and the end‐tidal sevoflurane concentration was changed. Predetermined end‐tidal sevoflurane concentrations for each group were determined using the Dixon up‐and‐down method. After the target concentration of sevoflurane was maintained for 5 min, the child’s trachea was intubated. Successful intubation was defined as excellent or good intubating conditions. The end‐tidal concentration (SD) of sevoflurane for successful tracheal intubation in 50% of children (ED50) were 5.16 (0.22)% in control, 3.27 (0.18)%, 1.81 (0.20)% and 1.01 (0.11)%, in remi0.1, remi0.2, and remi0.3 groups, respectively. Using probit analysis, the 95% effective dose (ED95) of sevoflurane were 5.60% (95% CI 5.35–7.66), 3.77% (95% CI 3.45–7.74), 2.18% (95% CI 1.96–3.86), 1.19% (95% CI 1.06–1.82) in control, remi0.1, remi0.2, and remi0.3 groups, respectively.
The effect of heart rate variability on request for labour epidural analgesia
Authors: Lao H.‐C. , Hseu S.‐S. , Huang C.‐J. , Chan K.‐H. , Kuo C.‐D.
Published: July 2009

Maternal heart rate variability of 62 parturients were compared based on their choice of using (epidural group, 44 women) or not using (control, 18 women) epidural analgesia. Baseline heart rate variability and visual analogue scores were recorded when the cervix of the parturient dilated to 2–4 cm, and paired data were collected 1 h later. We found that parturients in the epidural group had greater heart rate variability at the beginning of labour. Multiple logistic regression analysis identified percentage of absolute difference in successive RR intervals exceeding 20 ms as the best indicator of choosing epidural analgesia. Almost all heart rate variability measures were unchanged 1 h later in both groups. We concluded that parturients who chose epidural analgesia had greater heart rate variability, and that percentage of absolute difference in successive RR intervals exceeding 20 ms could reflect their likelihood of requesting epidural analgesia at the beginning of labour.
Anti-epidermal growth factor receptor monoclonal antibodies in cancer therapy
Authors: Martinelli E , De Palma R , Orditura M , De Vita F , Ciardiello F
Published: July 2009

The epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor involved in the proliferation and survival of cancer cells. EGFR is the first molecular target against which monoclonal antibodies (mAb) have been developed for cancer therapy. Here we review the mechanisms underlying the effects of EGFR-specific mAb in cancer therapy. The efficacy of EGFR-specific mAb in cancer occurs thanks to inhibition of EGFR-generated signalling; furthermore, the effects of antibodies on the immune system seem to play an important role in determining the overall anti-tumour response. In this review, attention is focused on cetuximab and panitumumab, two mAb introduced recently into clinical practice for treatment of metastatic colorectal and head and neck cancer which target the external part of EGFR.
Phylogenetic analysis identifies many uncharacterized actin‐like proteins (Alps) in bacteria: regulated polymerization, dynamic instability and treadmilling in Alp7A
Authors: Derman Alan I. , Becker Eric C. , Truong Bao D. , Fujioka Akina , Tucey Timothy M. , Erb Marcella L. , Patterson Paula C. , Pogliano Joe
Published: July 2009

Actin, one of the most abundant proteins in the eukaryotic cell, also has an abundance of relatives in the eukaryotic proteome. To date though, only five families of actins have been characterized in bacteria. We have conducted a phylogenetic search and uncovered more than 35 highly divergent families of actin‐like proteins (Alps) in bacteria. Their genes are found primarily on phage genomes, on plasmids and on integrating conjugative elements, and are likely to be involved in a variety of functions. We characterize three Alps and find that all form filaments in the cell. The filaments of Alp7A, a plasmid partitioning protein and one of the most divergent of the Alps, display dynamic instability and also treadmill. Alp7A requires other elements from the plasmid to assemble into dynamic polymers in the cell. Our findings suggest that most if not all of the Alps are indeed actin relatives, and that actin is very well represented in bacteria.
Sinorhizobium meliloti CpdR1 is critical for co‐ordinating cell cycle progression and the symbiotic chronic infection
Authors: Kobayashi Hajime , De Nisco Nicole J. , Chien Peter , Simmons Lyle A. , Walker Graham C.
Published: July 2009

ATP‐driven proteolysis plays a major role in regulating the bacterial cell cycle, development and stress responses. In the nitro ‐fixing symbiosis with host plants, Sinorhizobium meliloti undergoes a profound cellular differentiation, including endoreduplication of the
ome. The regulatory mechanisms governing the alterations of the S. meliloti cell cycle in planta are largely unknown. Here, we report the characterization of two cpdR homologues, cpdR1 and cpdR2, of S. meliloti that encode single‐domain response regulators. In Caulobacter crescentus, CpdR controls the polar localization of the ClpXP protease, thereby mediating the regulated proteolysis of key protein(s), such as CtrA, involved in cell cycle progression. The S. meliloti cpdR1‐null mutant can invade the host cytoplasm, however, the intracellular bacteria are unable to differentiate into bacteroids. We show that S. meliloti CpdR1 has a polar localization pattern and a role in ClpX positioning similar to C. crescentus CpdR, suggesting a conserved function of CpdR proteins among α‐proteobacteria. However, in S. meliloti, free‐living cells of the cpdR1‐null mutant show a striking morphology of irregular coccoids and aberrant DNA replication. Thus, we demonstrate that CpdR1 mediates the co‐ordination of cell cycle events, which are critical for both the free‐living cell division and the differentiation required for the chronic intracellular infection.
Functional Role of Feline Zona Pellucida Protein 4 Trefoil Domain: A Sperm Receptor or Structural Component of the Domestic Cat Zona Pellucida?
Authors: Braun BC , Ringleb J , Waurich R , Viertel D , Jewgenow K
Published: July 2009

Contents

The trefoil domain (TFD) is a protein structure characterized by six cysteines, which form a typical three‐loop structure by three disulphide bridges. It is assumed that two of these loops generate a hydrophobic groove, which could be a binding site for carbohydrate residues or proteins. The zona pellucida (ZP) protein, ZP4, contains such a TFD. The carbohydrate‐/protein‐binding property of TFD allows us to assume a potential sperm receptor function of this domain. Additionally, gastrointestinal trefoil peptides are stable against proteases; therefore, a structural role of TFD within the ZP might also be possible. We were able to show that the synthesized and natural folded feline TFD (fTFD) expresses the typical protease resistance that vanished under reducing conditions and after substitution of cysteine residues within the peptide. Furthermore, an antibody directed against the first loop of fTFD was almost unable to bind to intact in vitro mature cat oocytes. Pre‐incubation of oocytes in the reducing agent (DDT), however, improved antibody binding substantially. Therefore, we suggest structural masking of the fTFD domain within the intact ZP. An interaction between fTFD and feline sperm cells was examined using several methods, including immunocytochemistry, immunoelectron microscopy, co‐immunoprecipitation and far western blot, but we found no indication for an involvement of TFD in the primary sperm binding to the ZP. To summarize, there is increasing evidence that the TFD of fZP4 has a structural rather than a sperm‐binding function.
In Vitro Compaction of Germinal Vesicle Chromatin is Beneficial to Survival of Vitrified Cat Oocytes
Authors: Comizzoli P , Wildt DE , Pukazhenthi BS
Published: July 2009

Contents

The immature cat oocyte contains a large‐sized germinal vesicle (GV) with decondensed chromatin that is highly susceptible to cryo‐damage. The aim of the study was to explore an alternative to conventional cryopreservation by examining the influence of GV chromatin compaction using resveratrol (Res) exposure (a histone deacetylase enhancer) on oocyte survival during vitrification. In Experiment 1, denuded oocytes were exposed to 0, 0.5, 1.0 or 1.5 mmol/l Res for 1.5 h and then evaluated for chromatin structure or cultured to assess oocyte meiotic and developmental competence in vitro. Exposure to 1.0 or 1.5 mmol/l Res induced complete GV chromatin deacetylation and the most significant compaction. Compared to other treatments, the 1.5 mmol/l Res concentration compromised the oocyte ability to achieve metaphase II (MII) or to form a blastocyst. In Experiment 2, denuded oocytes were exposed to Res as in Experiment 1 and cultured in vitro either directly (fresh) or after vitrification. Both oocyte types then were assessed for meiotic competence, fertilizability and ability to form embryos. Vitrification exerted an overall negative influence on oocyte meiotic and developmental competence. However, ability to reach MII, achieve early first cleavage, and develop to an advanced embryo stage (8–16 cells) was improved in vitrified oocytes previously exposed to 1.0 mmol/l Res compared to all counterpart treatments. In summary, results reveal that transient epigenetic modifications associated with GV chromatin compaction induced by Res is fully reversible and beneficial to oocyte survival during vitrification. This approach has allowed the production of the first cat embryos from vitrified immature oocytes.
Diagnosis of Endometritis in the Bitch: A New Approach
Authors: Fontaine E , Levy X , Grellet A , Luc A , Bernex F , Boulouis HJ , Fontbonne A
Published: July 2009

Contents

There are a few investigations into endometritis in the bitch and its relationship with failure to conceive remains unclear. This may be because of the difficulty in collecting uterine samples for further investigations. Recently, transcervical catheterization by vaginal endoscopy has been introduced allowing the evaluation of the endometrium. In this study, uterine cytology and bacteriology were evaluated in 26 infertile bitches. Endometritis was bacterial in origin in most cases (70% of affected bitches), but these results may be underestimated, as some other pathogens (anaerobic bacteria, mycoplasms and fungi) were not investigated. Endometritis, in our opinion, should be investigated in each case of unexplained infertility in bitches. The method used here seems reliable although defining more accurate classification criteria will improve the efficiency of this non‐invasive technique.
Post‐Partum Involution of the Canine Uterus – Gross Anatomical and Histological Features
Authors: Orfanou DC , Ververidis HN , Pourlis A , Fragkou IA , Kokoli AN , Boscos CM , Taitzoglou IA , Tzora A , Nerou CM , Athanasiou L , Fthenakis GC
Published: July 2009

Contents

We aimed to study the normal puerperium in the bitch. Ovariohysterectomy was performed in nine bitches, each at a different day after normal whelping; their genital tract was subject to gross anatomical examination, as well as to histological examination and electron microscopy scanning. Corpora albicans were evenly distributed in the left and right ovaries and placental sites were evenly distributed among left and right uterine horns. Placental sites were initially of dark green to grey colour, later becoming dark brown; their length and height progressively decreased. Height of the myometrium and diameter of the uterine glands progressively decreased. Trophoblast‐like cells were consistently observed at the placental sites and on the surface of the interplacental areas, at all time points where hysterectomy had been performed. It is suggested that involution of the canine genital tract can last up to 3 months and is slow. Continuous (up to D84 post‐partum) presence of prominent placental sites should be considered a normal feature of canine uterine post‐partum involution.
Lactoferrin in Canine Sera: A Pyometra Study
Authors: Bartoskova A , Adlerova L , Kudlackova H , Leva L , Vitasek R , Faldyna M
Published: July 2009

Contents

The concentration of lactoferrin was measured in canine sera from groups of healthy male dogs as well as pregnant and non‐pregnant female dogs and was compared with that of bitches with pyometra. Lactoferrin concentrations were higher in bitches with pyometra. The role of elevated lactoferrin concentrations in the suppression of lymphocyte activity was examined in sera from bitches with pyometra in a series of investigations. Although the sera from bitches with pyometra were capable of suppressing lymphocyte activity, lactoferrin was not found to be involved in this action.
Effects of the Anti‐Progestin Aglepristone on the Uterine Tissue of Cats Administered Medroxyprogesterone Acetate
Authors: Muphung W , Rungsipipat A , Chatdarong K
Published: July 2009

Contents

The effect of aglepristone, a progesterone receptor antagonist, on feline endometrial proliferation induced by medroxyprogesterone acetate (MPA), a contraceptive progestin, was investigated. Three groups each of six cats were studied: Group A, during inter‐oestrus; Group B, given 50 mg MPA; Group C, receiving 50 mg MPA followed by 10 mg/kg aglepristone twice at 24‐h interval 3 weeks later. Ovariohysterectomy was performed, and uterine tissue was collected from the mid part of the horn when the cats were confirmed as being in inter‐oestrus (Group A), 3 weeks after the MPA administration (Group B), or 2 weeks after aglepristone administration (Group C). Uterine weights, relative uterine weights and uterine diameters were determined. The endometrial and myometrial thicknesses and the endometrial/myometrial ratios were determined in histological sections. Histological sections were also immunostained for proliferative activity [anti‐proliferative cell nuclear antigen (PCNA) antibody], and progesterone receptor (anti‐hPR) and percentage of positive cells in luminal vs glandular epithelium were determined for both parameters. PCNA and all morphological parameters except endometrial thickness were increased (p < 0.05) by MPA, and progesterone receptor was decreased compared to untreated cats. Aglepristone treatment had no significant effect compared to MPA alone. However, glandular proliferative activity was usually but not significantly lower in Group C than in Group B, suggesting a potential effect of the anti‐progestin that might be clinically beneficial. Alternatively, this possible effect in the aglepristone group may reflect the longer time after MPA that these animals were examined. Whether lack of significant effect of the anti‐progestin was because of too high dose of MPA relative to the dose of aglepristone, the delay of 14 days in obtaining tissues after aglepristone treatment, or simply an insufficient duration of aglepristone treatment requires further study.
Effect of Catalase and Superoxide Dismutase on Motility, Viability and Acrosomal Integrity of Frozen‐Thawed Cat Spermatozoa
Authors: Thiangtum K , Pinyopummin A , Hori T , Kawakami E , Tsutsui T
Published: July 2009

Contents

The aim of this study was to evaluate the effect of antioxidant catalase (CAT) and superoxide dismutase (SOD) in semen extender on motility, viability and acrosomal integrity of frozen‐thawed cat spermatozoa. Semen was collected by using an artificial vagina from five domestic cats (two ejaculates/cat). Spermatozoa were diluted in egg yolk Ttris‐fructose citrate solution (EYT‐FC) without glycerol and cooled at 4°C for 1 h, then diluted further with EYT‐FC with glycerol (7% final concentration) and 400 IU/ml of CAT (treatment 1) or SOD (treatment 2) or without antioxidants (control). Before freezing using a styrofoam box, diluted spermatozoa filled in 0.25‐ml straws were equilibrated for 1 h at 4°C. After thawing, spermatozoa were assessed for motility, viability and acrosomal integrity. Cryopreservation significantly impaired sperm motility, viability and acrosomal integrity (p < 0.05). However, motility, viability and acrosomal integrity of frozen‐thawed cat spermatozoa in the EYT‐FC with CAT, SOD and without the antioxidants were not significantly different. The average percentages of spermatozoa motility after thawing compared between control, treatment 1 and treatment 2 group were 43.5 ± 3.2, 42 ± 4.1 and 38 ± 4.5; for viability: 44.8 ± 3.5, 50.6 ± 5.7 and 47.1 ± 4.1 and for acrosomal integrity: 45 ± 3.5, 44.9 ± 3.4 and 44.4 ± 3.3, respectively. In conclusion, adding CAT and SOD to EYT‐FC did not improve motility, viability and acrosomal integrity in cryopreserved cat spermatozoa.
Ultrasound as a Mechanical Method for Male Dog Contraception
Authors: Leoci R , Aiudi G , De Sandro Salvati A , Silvestre F , Binetti F , Lacalandra GM
Published: July 2009

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Therapeutic ultrasound (1.5 W/cm2) was investigated for its effect upon testicular size and consistency and semen quality in five dogs. Dogs were treated every other day with a total of three treatments and were examined up to 2 weeks after treatment. There was some tenderness after treatment and a significant decrease in testicular size and semen quality. This method may provide a suitable contraception technique in dogs and requires further investigation.
Fertilizing Capacity of Frozen Epididymal Sperm Collected from Dogs
Authors: Martins MIM , Padilha LC , Souza FF , Lopes MD
Published: July 2009

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The collection of epididymal sperm may be a valuable tool for canine reproduction especially since it can enable collection of cells after death of a valuable dog. The aim of the present study was to evaluate the viability of epididymal sperm after freeze‐thawing. Epididymides were obtained from four adult dogs by elective orchiectomy. The caudal portion of the epididymides and part of the deferential ducts were squeezed by means of an anatomic clamp into a Petri dish containing either 0.9% saline solution (Group 1) or Ringer solution without lactate (Group 2). Samples were centrifuged at 800 × g for 10 min, the supernatant was removed and the pellet was diluted in one step with a Tris/citric acid/OEP (Orvus Es Paste) extender containing 7% glycerol and subjected to semen freezing. Oocytes were obtained from canine ovaries, after ovariohysterectomy. Only oocytes that were approximately 100 μm in diameter, with a dark ooplasm surrounded by three‐ or four‐well formed cumulus cell layers were used for sperm testing. Frozen semen samples were thawed in a water bath at 70°C for 8 s and analysed at room temperature for sperm motility and velocity. Oocytes were incubated with spermatozoa in humidified atmosphere containing 5% CO2 at 38°C for 18 h. Morphological and functional characteristics of spermatozoa were similar in both groups. However, the percentage of sperm cells bound to oocytes was significantly higher in Group 2 than in Group 1. This result suggests that the Ringer solution without lactate was a more suitable medium for collecting epididymal canine sperm than 0.9% saline.
Effect of Daily Food Supplementation with Essential Fatty Acids on Canine Semen Quality
Authors: Da Rocha AA , Da Cunha ICN , Ederli BB , Albernaz AP , Quirino CR
Published: July 2009

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Polyunsaturated fatty acids are important membrane components that influence membrane integrity and fluidity. In the present study, the effect of oral supplementation for 60 days with essential fatty acids (omega 3, 6 and 9) and vitamin E on canine semen quality was evaluated. Sixteen dogs were selected for the experiment; eight were used as the control group and eight received the fatty acid supplemented diet for 60 days. Semen samples were taken every 15 days during the entire experimental period and were analyzed for volume (ml), motility (%), vigour (0–5), concentration (×106/ml), morphology of spermatozoa (%), plasma membrane integrity (%; using the hyposmotic swelling test) and thermoresistance (motility and vigour after 4 h at 38°C). We concluded that, daily supplementation with omega 3, omega 6 and omega 9 fatty acids, together with vitamin E, for a period of 60 days, significantly increased the semen volume of the treated group after 15 days of supplementation; the vigour and concentration of spermatozoa were superior after the first month of supplementation, while the percentage of morphologically abnormal spermatozoa decreased and the cells were protected against thermal stress.
Effect of an Injectable Cabergoline Formulation on Serum Prolactin (PRL) and Milk Secretion in Early Postpartum Beagle Bitches
Authors: Romagnoli S , Milani C , Perin S , Ballabio R , Stelletta C , Mollo A , Gelli D
Published: July 2009

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This study was conducted in order to evaluate effects on prolactin (PRL) concentration and mammary milk secretion of an injectable cabergoline formulation administered to five lactating Beagle bitches during early postpartum (PP). Bitches were bled twice daily (from PP day 3 to PP day 12) and then daily (from PP day 13 to PP day 16) to assay serum PRL. On PP day 6, a subcutaneous (SC) injection of 0.1 ml/kg of placebo was administered. On PP day 9, a SC 0.1 ml/kg dose of injectable cabergoline was administered. All bitches were checked for milk production, using a clinical scoring in order to quantify milk expression from each teat. A circadian variation of serum PRL was evident during the 6 days of pre‐treatment monitoring. The day after cabergoline injection, an 80% decrease of PRL serum concentration was observed (p < 0.05). The circadian oscillatory pattern of PRL secretion disappeared after administration of cabergoline, and PRL values remained significantly lower than in the previous days for the first 60 h following treatment (p < 0.001). Milk production was drastically reduced when comparing pre‐treatment to post‐treatment scores (p < 0.001). A single dose of injectable cabergoline caused a significant reduction in serum PRL concentration and a significant reduction in milk flow. The injectable formulation of cabergoline appeared to be safe and well tolerated.
Clinical Use of Deslorelin for the Control of Reproduction in the Bitch
Authors: Romagnoli S , Stelletta C , Milani C , Gelli D , Falomo ME , Mollo A
Published: July 2009

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This study was conducted to evaluate clinical efficacy of deslorelin for inhibiting reproduction in the bitch. Ten adult healthy bitches or bitches with mammary neoplasia for which owners were requesting suppression of cyclicity without performing gonadectomy were administered a 4.7‐ or a 9.4‐mg deslorelin implant subcutaneously. The first implant of deslorelin was administered in anoestrus (n = 5) or in dioestrus (n = 5). Treatment was repeated every 5 months for as long as necessary based on the clinical situation of the dog and owner’s desires. Some of the bitches implanted in anoestrus came in heat within 4–15 days after treatment, while none of the bitches implanted in dioestrus showed heat during treatment. Suppression of reproductive cyclicity was successfully achieved in 6/10 bitches for 1–4 years. No behavioural and local/general side‐effects were observed in any of the treated bitches. The 4.7‐mg deslorelin implant may work well for suppression of cyclicity provided that it is administered in dioestrus and at intervals of 4.5 months. A 9.4‐mg implant may be more suitable for this use although its efficacy may also be shorter than 12 months. Owner compliance is an important limiting factor.
Thyroid Function and Infertility in the Dog: A Survey in Five Breeds
Authors: Segalini V , Hericher T , Grellet A , Rosenberg D , Garnier F , Fontbonne A
Published: July 2009

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In our study, a clinical and reproductive examination was undertaken in 204 dogs of five different breeds. Thyroxine and thyroid‐stimulating hormone plasma concentrations were assayed in order to assess the real incidence of hypothyroidism associated with reproductive disease. Among these animals, only two breeds were affected by hypothyroidism (4.5% of the Dogue de Bordeaux and 2.4% of the Leonbergers). Moreover, these animals did not suffer from any reproductive disease. Our study showed also that 70% of the male Dogue de Bordeaux were hypothyroxinemic compared with Great Danes, English Mastiff and Leonbergers whose male population was 100% normothyroidic. We found the same tendency in bitches. In our data, there was no difference in thyroxin plasma concentrations between normo‐ and hypofertile dogs, but our results were not statistically significant.
The Role of the Ovary for the Maintenance of Pregnancy in Cats
Authors: Tsutsui T , Suzuki Y , Toyonaga M , Oba H , Mizutani T , Hori T
Published: July 2009

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Plasma progesterone (P4) concentrations are maintained in pregnant cats until parturition, but become low in pseudopregnant cats 40–45 days after infertile mating. This difference in P4 concentrations is considered to be due to P4 secretion by the placenta of pregnant cats. Therefore, to clarify these points, we performed ovariectomy (OVX) at various stages of pregnancy, examined the pregnancy status and measured LH and P4 concentrations in peripheral, ovarian and uterine venous blood. After OVX, abortion occurred in 100% (5/5), 80% (4/5), 40% (2/5) and 60% (3/5) of Groups I (Day 35), II (Day 40), III (Day 45) and IV (Day 50) cats, respectively. In the remaining cats, normal delivery took place on days 63–69 [mean, 66.1 ± 1.1 (SE)] of pregnancy. The time to abortion after OVX was 4–8 (mean, 5.6 ± 0.8), 3–17 (mean, 8.0 ± 3.6), 10 and 11, and 2–4 (mean, 3.0 ± 0.7) days in Groups I, II, III and IV, respectively. The plasma P4 concentrations were 1–2 ng/ml in all groups on the day after OVX, decreasing to less than 1 ng/ml from the 2nd day onwards. The concentrations of P4 in ovarian venous blood at the time of OVX decreased with the stage of pregnancy, but were clearly higher than those in peripheral blood. The plasma P4 concentrations in uterine venous blood were similar to those in peripheral blood. These results suggest that peripheral P4 in pregnant cats is the result of P4 secretion secreted only by the ovarian corpus luteum, not by the placenta, but indicate that either P4 is not essential for the maintenance of pregnancy in cats from day 40–45 of pregnancy onwards, or that the placenta provides a local source of P4 that does not appear in measurable amounts in the peripheral circulation.
Leadership and Uncertainty: How Role Ambiguity Affects the Relationship between Leader Group Prototypicality and Leadership Effectiveness
Authors: Cicero Lavinia , Pierro Antonio , Van Knippenberg Daan
Published: July 2009

In social identity analyses of leadership the role of leader group prototypicality (the extent to which the leader is representative of the collective identity) in leadership effectiveness is emphasized. We extend this analysis by identifying role ambiguity as a situational influence that feeds into the desire to reduce uncertainty, as a moderator of the relationship between leader group prototypicality and indicators of leadership effectiveness (perceived effectiveness, job satisfaction and turnover intentions). Role ambiguity is proposed to lead people to turn to their group memberships, making leadership effectiveness more contingent on the extent to which leaders are group prototypical. Results of a survey of n=368 employees of four Italian companies supported this hypothesis. Role ambiguity and leader group prototypicality interacted in predicting perceived effectiveness, job satisfaction and turnover intentions, such that leader group prototypicality was more strongly related to leadership effectiveness for employees experiencing greater role ambiguity.
Contingencies versus External Pressure: Professionalization in Boards of Firms Affiliated to Family Business Groups in Late‐Industrializing Countries
Authors: Yildirim‐Öktem Özlem , Üsdiken Behlül
Published: July 2009

We examine the antecedents of professionalization in boards of firms affiliated to family business groups, increasingly recognized in the literature as the dominant form of big business organization in many late‐industrializing countries. Dimensions of board professionalization that we include in our study are board size, ratio of salaried executives and outsider presence. We compare predictions on board composition derived from contingency, institutional and power perspectives. Turkish family business groups, considered as an archetypal example of this form of organization, provide the empirical setting for the study, with data on 299 firms affiliated to ten different family business groups. Our results provide greater support for institutional and power perspectives, showing that, relative to internal and external complexity facing affiliate firms, institutional pressures and the presence of joint venture partners better predict board professionalization.