bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determinants of the streptococcal surface glycoprotein GspB that facilitate export by the accessory Sec system
Authors: Bensing Barbara A. , Takamatsu Daisuke , Sullam Paul M. 
Published: October 2005

SummaryGspB is a large cell‐surface glycoprotein expressed by Streptococcus gordonii M99 that mediates binding of this organism to human platelets. This adhesin is glycosylated in the cytoplasm, and is then transported to the cell surface via an accessory Sec system. To assess the structural features of GspB that are needed for export, we examined the effects of altering the carbohydrate moieties or the polypeptide backbone of GspB. Truncated, glycosylated variants of GspB were exported exclusively via the accessory Sec pathway. When glycosylation was abolished, the GspB variants were still exported by this pathway, but minor amounts could also be transported by the canonical Sec system. GspB variants with in‐frame insertions or deletions in the N‐terminus were not secreted, indicating that this domain is necessary for export. However, the N‐terminus is not sufficient for the transport of heterologous proteins, because C‐terminal fusion of passenger proteins to this domain hindered export. In contrast, fusion of GspB to a canonical signal peptide resulted in the efficient export of non‐glycosylated forms of the fusion protein via the canonical Sec pathway, whereas glycosylated forms could not be exported. Thus, the carbohydrate moieties and the atypical signal sequence of GspB interfere with export via the canonical pathway, and direct GspB towards the accessory Sec system.
Fur regulates acid resistance in Shigella flexneri via RyhB and ydeP
Authors: Oglesby Amanda G. , Murphy Erin R. , Iyer Vishwanath R. , Payne Shelley M. 
Published: October 2005

SummaryShigella flexneri requires iron for survival, and the genes for iron uptake and homeostasis are regulated by the Fur protein. Microarrays were used to identify genes regulated by Fur and to study the physiological effects of iron availability in S. flexneri. These assays showed that the expression of genes involved in iron acquisition and acid response was induced by low‐iron availability and by inactivation of fur. A fur null mutant was acid sensitive in media at pH 2.5, and acid sensitivity was also observed in the wild‐type strain grown under iron‐limiting conditions. Acid resistance of the fur mutant in minimal medium was restored by addition of glutamate during acid challenge, indicating that the glutamate‐dependent acid resistance system was not defective. Inactivation of ryhB, a small regulatory RNA whose expression is repressed by Fur, restored acid resistance in the fur mutant, while overexpressing ryhB increased acid sensitivity in the wild‐type strain. RyhB‐regulated genes were identified by microarray analysis. The expression of one of the RyhB‐repressed genes, ydeP, which encodes a putative oxidoreductase, suppressed acid sensitivity in the fur mutant. Furthermore, an S. flexneri ydeP mutant was defective for both glutamate‐independent and glutamate‐dependent acid resistance. The repression of ydeP by RyhB may be indirect, as real time polymerase chain reaction (PCR) experiments indicated that RyhB negatively regulates evgA, which encodes an activator of ydeP. These results demonstrate that the acid sensitivity defect of the S. flexneri fur mutant is due to repression of ydeP by RyhB, most likely via repression of evgA.
Characterization of a Methanosarcina acetivorans mutant unable to translate UAG as pyrrolysine
Authors: Mahapatra Anirban , Patel Asmita , Soares Jitesh A. , Larue Ross C. , Zhang Jun Kai , Metcalf William W. , Krzycki Joseph A. 
Published: October 2005

SummaryThe methyltransferases initiating methanogenesis from trimethylamine, dimethylamine and monomethylamine possess a novel residue, pyrrolysine. Pyrrolysine is the 22nd amino acid, because it is encoded by a single amber (UAG) codon in methylamine methyltransferase transcripts. A dedicated tRNACUA for pyrrolysine, tRNAPyl, is charged by a pyrrolysyl‐tRNA synthetase with pyrrolysine. As the first step towards the genetic analysis of UAG translation as pyrrolysine, a 761 base‐pair genomic segment in Methanosarcina acetivorans containing the pylT gene (encoding tRNAPyl) was deleted and replaced by a puromycin resistance cassette. The ΔppylT mutant lacks detectable tRNAPyl, but grows as wild‐type on methanol or acetate. Unlike wild‐type, the ΔppylT strain cannot grow on any methylamine, nor use monomethylamine as sole nitrogen source. Wild‐type cells, but not ΔppylT, have monomethylamine methyltransferase activity during growth on methanol. Immunoblot analysis indicated monomethylamine methyltransferase was absent in ΔppylT. The phenotype of ΔppylT reveals the deficiency in methylamine metabolism expected of a Methanosarcina species unable to decode UAG codons as pyrrolysine, but also that loss of pylT does not compromise growth on other substrates. These results indicate that in‐depth genetic analysis of UAG translation as pyrrolysine is feasible, as deletion of pylT is conditionally lethal depending on growth substrate.
An Extract of the Mushroom Agaricus blazei Murill Administered Orally Protects Against Systemic Streptococcus pneumoniae Infection in Mice
Authors: Bernardshaw S. , Johnson E. , Hetland G. 
Published: October 2005

AbstractThe aim was to investigate the antibacterial effect of the biologically active and edible mushroom Agaricus blazei Murill (AbM). A water extract of AbM or PBS control was administered orally before or with challenge to NIH/OlaHsd mice, experimentally infected intraperitoneally with the moderately virulent Streptococcus pneumoniae serotype 6B. End points were bacteraemia and survival rate. The AbM extract, protected against systemic S. pneumoniae 6B infection in the mice. It was most effective when given 24 h before inoculation but did also have protective effects when given together with challenge compared with control. The lack of antibiotic effect on pneumococci in vitro and increased levels of cytokines MIP‐2 and TNF‐α in the serum of mice receiving AbM extract, indicated that the protective effect of AbM was due to the involvement of the native immune system. This is the first report of anti‐infection effects of AbM in vivo. Our results suggest that AbM extract may be useful as additional prophylactic and possibly therapeutic treatment against bacterial and possibly other infections in humans.
Human IgG but not IgM Antibodies can Protect Mice from the Challenge with Live O6 Escherichia coli
Authors: Pontes G. N. , Massironi S. G. , Arslanian C. , Palmeira P. , Carneiro‐Sampaio M. M. S. , Nagao A. T. 
Published: October 2005

AbstractWe evaluated the ability of human anti‐lipopolysaccharide (LPS) O6 immunoglobulin G (IgG) and IgM antibodies to protect mice challenged with Escherichia coli serotype O6:K2ac. Purified whole IgG, commercial gammaglobulin, whole IgM‐effluent, pool of normal human serum (NHS), agammaglobulinaemic serum (test groups) or phosphate‐buffered saline (control group) was injected into adult male 18 h before a challenge with viable O6 E. coli. The mortality rate was assessed over a period of 72 h. To determine the opsonic and phagocytic activity of the antibody isotypes, we incubated peritoneal macrophages from the control and test groups collected at different times after challenge with the live bacteria with acridine orange for fluorescent analysis. Tumour necrosis factor (TNF)‐α and interleukin (IL)‐6 were quantified in serum of both the test and control groups. All mice that received commercial gammaglobulin or NHS survived. Purified whole IgG (containing 1.1 mg/l of anti‐LPS O6 IgG antibodies) protected 87.5% of the animals tested in this experiment, while whole IgM‐enriched effluent with 1.5 mg/l of anti‐LPS O6 IgM antibodies protected only 12.5%. The agamma serum showed no protective capacity compared with PBS (serving as control). The minimal concentration of anti‐LPS O6 IgG antibodies able to protect 50% of animals was 0.137 mg/l of purified whole IgG. Whole IgM‐enriched effluent showed no protective capacity independently of the concentration tested (0.048–17.0 mg/l of anti‐LPS O6 IgM antibodies). Fluorescent analysis of peritoneal macrophages from animals pretreated with purified whole IgG showed no bacteria at 8 h after the challenge. By contrast, whole IgM effluent showed an increasing number of live bacteria at the same time. Mice that had received whole IgM effluent (1.5 mg/l of anti‐LPS O6 IgM antibodies) before the challenge with LPS O6 presented 20.5 µg/l of IL‐6 and 1.5 µg/l of TNF‐α. Serum from animals pretreated with purified IgG did not present any detectable pro‐inflammatory cytokine. Our findings suggest that IgG but not IgM antibodies protect animals from a challenge with E. coli O6 serotype.
Immunohistochemical Identification of Amyloid, Using an Anti‐human Serum Amyloid P Component (SAP) Antibody, is Possible in Ruminants but not in Dogs and Cats
Authors: Hartig W. , Leifsson P. S. , Nielsen O. L. 
Published: October 2005

SummaryAmyloidosis represents a heterogenous group of diseases that have in common the deposition of fibrils composed of proteins of beta‐pleated sheet structure, a structure which can be specifically identified by histochemistry using the Congo red or similar stains. Amyloid consists primarily of the amyloid fibrils but also of the amyloid P component (AP). This component, which is identical with the serum counterpart (SAP), is found in all types of human amyloid, and immunohistochemical identification of AP has been proposed as an adjunct to the universal, type‐independent diagnosis of human amyloidosis. In the present study of animal amyloidosis, we compared the amyloid‐specific Congo red stain with an immunohistochemical protocol using an anti‐human SAP antibody for the identification of amyloid in formalin fixed tissue samples. The species and types of amyloidoses investigated were: (i) seven cows, one yak (Bos grunniens), and one sheep affected with amyloidosis of presumed AA type, (ii) one dog with a pancreatic endocrine tumour producing amyloid of presumed AIAPP type, (iii) two cats with presumed AIAPP‐amyloidosis of the islets of Langerhans, one cat with presumed AA‐amyloidosis, and one cat with an amyloid‐producing odontogenic tumour. Intense immunostaining co‐localized with amyloid, identified by its congophilia and green birefringence, using a protocol without any antigen retrieval in each of the seven cows, the yak and the sheep. The method seemed more sensitive in the ruminants than the Congo red stain, but was unable to detect amyloid in the dog and the cats regardless of the application of various antigen retrieval protocols. However, specific identification of amyloid still rests on the Congo red method or similar histochemical techniques.
The Effect of Different Isolation Procedures on Canine Leucocyte Populations and on Lectin‐induced Lymphocyte Proliferation
Authors: De Bruin T. , De Rooster H. , Van Bree H. , Cox E. 
Published: October 2005

SummaryProliferation assays performed on peripheral blood mononuclear cells (PBMC) are commonly used in experimental and clinical immunology. A prerequisite for an in vitro assay is the ability to obtain relatively pure populations of mononuclear cells from whole blood, as contaminating polymorphonuclear cells may affect the proliferation of lymphocytes. Purification of canine leucocytes from whole blood is associated with difficulties in obtaining pure lymphocytes in high yields. The aim of this study was to optimize the lymphocyte purification from canine whole blood in terms of total cell recovery and purity, while not influencing the proliferation capacity of the isolated cells. To acquire optimal isolation of canine lymphocytes several density gradient media of different densities and osmolalities were examined. For optimal phagocyte removal, pre‐treatment of whole blood with carbonyl iron/arabic gum and/or adherence to fibrinogen pre‐coated polystyrene tissue flasks were examined. Lectin‐induced proliferation was used as measurement of cell activity of the obtained cell fractions after the different separation procedures. Canine blood pre‐treated with carbonyl iron/arabic gum followed by density gradient centrifugation with medium ‘G’ (density: 1.079 g/cm3, osmolality: 256 mOsm) and adherence to pre‐coated polystyrene tissue flask obtained the best PBMC cultures with a median lymphocyte purity of 88% and a median yield of recovered lymphocytes of 54%. This culture also resulted in the highest proliferation and subsequently the highest stimulation index upon lectin stimulation.
Effect of Insemination Volume on Uterine Contractions and Inflammatory Response and on Elimination of Semen in the Mare Uterus – Scintigraphic and Ultrasonographic Studies
Authors: Sinnemaa L. , Järvimaa T. , Lehmonen N. , Mäkelä O. , Reilas T. , Sankari S. , Katila T. 
Published: October 2005

SummaryThe effect of artificial insemination (AI) volume on uterine contractility and inflammation and on elimination of semen in the reproductive tract of mares was examined for 4 h after AI using two methods, scintigraphy and ultrasonography. The same doses were used in both methods: 2 and 100 ml of skim milk‐extended frozen semen. In the scintigraphic study, the number of reproductively normal mares was four per group and in the ultrasonographic study five per group. For scintigraphy, the semen was radiolabelled with technetium‐99m. The static scintigrams were acquired immediately before and 30, 60, 120, 180 and 240 min after AI. The activities in the vagina and uterus were calculated and the values for sperm that had been discharged from the mare were obtained by subtracting the counts for the uterus and vagina from the total radioactivity. The dynamic scintigrams were taken continuously for the first 30 min after AI and in 5‐min periods immediately after having acquired the static scintigrams. The uterine contractions were counted. In the ultrasonographic study, the mares were scanned before AI and at 5, 10, 15, 20, 25, 30, 60, 120, 150, 180, and 240 min after AI, for at least 1 min each time. The examinations were videotaped and contractions counted per minute. More contractions were observed with the ultrasonographic method than with the scintigraphic method. No difference was present in the number of contractions between the groups, except in the ultrasonographic study at 4 h, when the mares inseminated with 100 ml showed more contractions than did the mares inseminated with 2 ml. The intraluminal fluid was sampled with a tampon and by uterine lavage 4 h after AI in the ultrasonographic study. The numbers of polymorphonuclear leukocytes and spermatozoa were counted, but the differences between the groups were not significant. Under our experimental conditions and with the number of mares examined, the volume of the AI dose had an insignificant effect on contractility – with the exception at 4 h – and inflammatory reaction and on semen elimination in the uterus.
Influence of Partus Induction on the pH Value in the Blood of Newborn Piglets
Authors: Wehrend A. , Stratmann N. , Failing K. , Bostedt H. 
Published: October 2005

SummaryPartus induction is an important integrative component of reproduction management in the swine industry. In this context, the question is to what extent the application of uterotonic substances may influence the vitality of piglets. The blood pH value is used as a laboratory objective diagnostic parameter of neonatal acidosis. This parameter of the acid–base balance was examined in piglets born spontaneously at the 115th to 116th day of gestation (group 1, n = 57) and after two different partus induction protocols starting at the 114th day of gestation (group 2: combination of 175 μg of cloprostenol and 20 IU of oxytocin, n = 55; group 3: 175 μg of cloprostenol and 35 μg of carbetocin, n = 56). Initial blood samples were taken from each piglet at birth and 2 h later. The results show that the different protocols have no negative influence on the initial pH value and the compensation of neonatal acidosis until the second hour post‐natum.
Immunohistochemical Observations on TSH Secreting Cells in Pituitary Glands of Goat Kids with Congenital Goitre
Authors: Ozmen O. , Haligur M. 
Published: October 2005

SummaryPituitary glands of normal‐termed stillborn goat kids with congenital goitre and normal‐termed stillborn goat kids without congenital goitre were examined macroscopically, histopathologically and immunohistochemically. Thyroid glands of these animals were also examined grossly and microscopically. The pituitary glands of kids with goitre were larger than those of normal kids, and on histopathological examination there was hyperplasia of the acidophil cells in the ventral part of the glands. However, it was impossible to distinguish thyroid stimulating hormone (TSH)‐secreting cells from other acidophil cells in sections stained with haematoxylin and eosin (HE). Red granules were observed in the cytoplasm of these hyperplastic cells in periodic acid‐Schiff (PAS)‐stained sections. Sections were also immunostained with an antibody against TSH using the streptavidin–biotin peroxidase technique. Immunohistochemistry revealed TSH‐secreting cells to have increased in number in the pituitary glands of kids with congenital goitre because of the extensive proliferation when compared with those of normal kids. The present study indicated that the presence of multiple fetuses (twins or triplets) may be a predisposing factor for congenital goitre.
Enhanced Non‐esterified Fatty Acids and Corticosterone in Blood Plasma of Chickens Treated with Insulin are Significantly Depleted by Reverse T3: Minor Changes in Hypoglycaemia
Authors: Niezgoda J. , Bobek S. , Wrońska‐Fortuna D. 
Published: October 2005

SummaryPreviously, it has been observed that dexamethasone or adrenaline‐induced hyperlipaemia in blood of chicken was significantly reduced after administration of reverse triiodothyronine (rT3). The present experiment was performed on chicken to determine the altered circulating non‐esterified fatty acids (NEFA) induced by physiologically enhanced endogenous corticosterone and catecholamines may also be influenced by rT3. Rise of both hormones were induced by insulin administration. Changes in circulating glucose, corticosterone and catecholamines were additionally measured. Following insulin injection blood glucose fell on the average by 32.7% below control at 2 h of the experiment. Additional treatment with rT3(rT3 + insulin group) gradually attenuated this decrease and at 4 and 6 h of the experiment it was 17.1% and 12.9% below control, respectively, suggesting on slight inhibition by rT3of insulin‐stimulated glucose utilization. Exposure to insulin significantly increased NEFA levels to about 670% above control group. Additional treatment with rT3reduced this increase to 309% of control, suggesting inhibition of lipolysis by rT3. Similar alterations were observed in plasma corticosterone levels. Insulin treatment peaked the corticosterone levels maximally by 507.6% above control. Additional treatment with rT3abolished this rise in the averages to 194.2% above control, possibly by interaction of rT3with hypothalamo‐adrenal axis. Insulin injection increased plasma catecholamines on the average by 21.5% and 53.4% for adrenaline and noradrenaline respectively. Supplementary treatment with rT3intensified this rise by 55.6% and 71.6% respectively. The obtained results suggest on inhibitory effect of rT3on hypoglycaemia, hyperlipaemia and plasma corticosterone concentrations in chickens treated with insulin. Contrary to this, rT3enhanced the rise of plasma catecholamines due to insulin treatment. The obtained data favour the assumption that hypometabolic properties of rT3depends mainly upon reduced supply of NEFA as a result of restricted lipolysis and to a lesser extent upon the supply of glucose.
Osseous Lesion of the Calcaneus Following the Use of Shock Wave Therapy in a Horse
Authors: Diakakis N. , Patsikas M. N. , Dessiris A. K. 
Published: October 2005

SummaryAn 8‐year‐old Dutch warmblood gelding was presented with a mechanical lameness (2/10) because of the presence of a soft tissue injury on the top of the right tuber calcanei. Plain radiographs of the tarsus demonstrated the presence of soft tissue swelling caudal to the right tuber calcanei, without osseous involvement, and ultrasonography revealed excessive scar tissue within and around the superficial digital flexor tendon. Extra‐corporeal shock wave therapy was applied on the right hock to decrease the amount of scar tissue. One month after the therapy the lameness was greater (3/10) and a marginal increase in the size of the swelling was found. Periosteal new bone formation associated with an ill‐defined radiolucent area and two bony fragments were detected radiographically at the caudo‐proximal aspect of the right tuber calcanei. A blister containing oil of croton, camphor, pine and thyme, turpentine and cantharides was applied on the right calcaneus. Twenty days after blister application, the size of the swelling had been reduced by 50% and the degree of lameness had also been decreased (1/10). On clinical re‐evaluation 6 months after treatment, the degree of lameness was stable (1/10) and flexion test of the limb was negative.
Larval head anatomy ofHeterogynis penella(Zygaenoidea, Heterogynidae), and a general discussion of caterpillar head structure (Insecta, Lepidoptera)
Authors: Vegliante F. 
Published: October 2005

AbstractThe internal head anatomy (and the peculiar integumental structure of the epicranial notch region) ofHeterogynis penellalarvae are described; special attention is paid to the skeleto‐muscular and nervous systems and to the cephalic glands. Transverse ligaments connect the apodemes of the mandibular adductor muscles of both sides and the anterior maxillo‐labial articulations of both sides. The two ligaments are linked to each other by a thin, apparently acellular membrane. An accessory, trilobed mandibular gland is present. A putative stretch receptor, connecting the oblique dorsal cibarial dilators of both sides, is described for the first time in a lepidopterous larva and its importance in assessing the homology of these muscles is discussed. The presence of cibarial sensilla, previously predicted in other caterpillars on the basis of behavioural experiments and observations of the nerve pattern, is confirmed. The structural diversity of larval head anatomy in ditrysian Lepidoptera is discussed, with particular emphasis on the innervation of the corpora cardiaca and corpora allata and of the sensilla of the head capsule.
Breeding success of the colonist species Bubulcus ibis (Linnaeus, 1758) and four native species
Authors: Petry Maria Virginia , Fonseca Vanda Simone Da Silva 
Published: October 2005

AbstractThis work evaluated the breeding success of Bubulcus ibis (Ardeidae), Egretta thula, Nycticorax nycticorax, Phimosus infuscatus and Plegadis chihi in Rio Grande do Sul during two consecutive nesting seasons. Mean clutch size for B. ibis was 2.59 in 1998/1999 and 2.49 in 1999/2000. The species with both the smallest and largest clutch was P. infuscatus, with 2.04 in 1999/2000, and 3.16 in 1998/1999. The highest mean number of nestlings per nest was 2.86 for P. chihi in 1998/1999 and the lowest was 1.85 for B. ibis in 1998/1999 and P. infuscatus in 1999/2000. In both nesting seasons all the species had major success, laying three eggs and raising two nestlings, exept for B. ibis. The breeding success for P. chihi varied from 1.54 young/nest in 1998/1999 to 0.4 in 1999/2000, whereas B. ibis ranged from 1.16 in the first period to 0.99 in the second.