IDENTIFICAÇÃO DA TOXINA BOTULÍNICA TIPO C E D EM BOVINO – RELATO DE CASO

RESUMO O presente trabalho descreve um quadro de botulismo em bovino fêmea proveniente do Município de São José dos Campos, SP, que apresentou no pós-parto um quadro de paralisia flácida de membros posteriores seguida de óbito, em propriedade de criação extensiva de corte. Foi possível detectar a toxina botulínica tipos C e D a partir dos conteúdos ruminal e intestinal pela técnica de soroneutralização em camundongo. Surtos de botulismo em bovinos são frequentes no Brasil, geralmente devido ao hábito de osteofagia, que leva à ingestão de toxina produzida pelo bacilo anaeróbio Clostridium botulinum. A falta de suplementação mineral pode ser um fator desencadeador do quadro de botulismo, aliado a ausência de um manejo adequado.

Evaluating risk of hospitalization with G-CSF use in real-world oncology practice

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Background: Limited published data exist on how granulocyte colony-stimulating factor (G-CSF) treatment patterns affect risk of neutropenia-related hospitalizations. This study examines prophylactic vs. delayed use of G-CSF and compares the effectiveness of prophylaxis with filgrastim (FIL) vs. pegfilgrastim (PEG). Methods: A retrospective analysis of administrative claims from U.S. commercial health plans identified adult patients with non-Hodgkin's lymphoma, breast, or lung cancer, treated with chemotherapy between July 2004 and January 2008. For these patients, the first course of chemotherapy and each unique cycle with use of G-CSF (FIL or PEG) was identified and designated ‘prophylaxis’ if used within the first 5 days of each cycle, or ‘delayed', if after day 5. The risk of neutropenia-related hospitalization was then evaluated on a cycle basis. A generalized estimating equation (GEE) was used to adjust for baseline demographics and clinical characteristics. Results: Among 5,571 patient-cycles identified: 87.4% were prophylactic and 12.6% were delayed G-CSF. PEG use was primarily prophylactic (93.6%) in contrast to use of FIL which was delayed in 62.5% of patient-cycles. The rate of neutropenic hospitalization was 1.2% for prophylaxis (n=59) and 3.7% for delayed G-CSF (n=26) (P < 0.001). Among prophylactic patient-cycles, the neutropenic hospitalization rate was lower with PEG than FIL (1.1% (n=51) vs. 3.5% (n=8), p = 0.001). Multivariate analyses using GEE model showed consistent trends (Table). Conclusions: Prophylactic G-CSF use was associated with lower neutropenic hospitalization risk than delayed use. Among prophylactic use in real-world oncology practice, PEG was associated with about a two-thirds lower risk of neutropenic hospitalization compared with FIL.

[Table: see text]

[Table: see text]

Assessment of effects of chromated copper arsenate (CCA)-treated timber on nontarget epibiota by investigation of fouling community development at seven European sites

To assess the effect of the anti-marine-borer timber preservative CCA (a pressure-impregnated solution of copper, chromium, and arsenic compounds) on nontarget epibiota, fouling community development was investigated. Panels of Scots pine treated to target retentions of 12, 24, and 48 kg CCA per m3 of wood (covering the range of retentions recommended for marine use) plus untreated controls were submerged at seven coastal sites (Portsmouth, UK; La Tremblade [two sites], France; Ria Formosa, Portugal; Sagres, Portugal; Kristineberg, Sweden; Athens, Greece). The fouling community on the surfaces of the panels was assessed both qualitatively and quantitatively after 6, 12, and 18 months of exposure. Multivariate statistical methods were used to compare community structure between panel treatments. Panels treated to the three CCA loadings supported very similar fouling assemblages, which in most cases had higher numbers of taxa and individuals than assemblages on untreated panels. No detrimental effects on epibiota due to CCA preservatives were detected at any of the treatment levels at all seven exposure sites, suggesting that the range of environmental conditions at the sites had no bearing on preservative impact on fouling biota. Differences in community structure between CCA-treated and untreated panels may be due to enhanced larval settlement on CCA-treated timber by some species as a result of modifications to the surface properties of the timber by the preservative. Possible reasons for the higher numbers of certain species on the surface of CCA-treated panels are discussed.

Programmed cell death eliminates all but one embryo in a polyembryonic plant seed

Development of multiple embryos from a single zygote, the phenomenon called monozygotic polyembryony, is a widespread reproductive strategy found in higher plants and especially in gymnosperms. The enigma of plant monozygotic polyembryony is that only one embryo in a polyembryonic seed usually survives while the others are eliminated at an early stage. Here we report that programmed cell death (PCD) is the major mechanism responsible for elimination of subordinate embryos in a polyembryonic seed. Using post-fertilized pine (Pinus sylvestris) ovules, we show that once the dominant embryo is selected and, subsequently, the entire female gametophyte is affected by PCD, the cells of subordinate embryos initiate an autolytic self-destruction program. The progression of embryonic PCD follows a rigid basal-apical pattern, first killing the most basally situated cells, adjacent to the suspensor, and then proceeding towards the apical region until all cells in the embryonal mass are doomed. Our data demonstrate that during polyembryony, PCD serves to halt competition among monozygotic embryos in order to ensure survival of one embryo.

Screening of basidiomycete fungi for the quinone-dependent sugar C-2/C-3 oxidoreductase, pyranose dehydrogenase, and properties of the enzyme from Macrolepiota rhacodes

Mycelial cultures of 76 strains of lignocellulose-degrading basidiomycete fungi were screened for the activity of pyranose dehydrogenase, a novel sugar oxidoreductase recently detected in Agaricus bisporus. Of these fungi, 37 strains belonging to seven phylogenetically related genera of mostly litter-decomposing Agaricales were positive for the dehydrogenase, based on activity assays towards D-glucose with 1,4-benzoquinone or ferricenium ion as electron acceptors, and on TLC/HPLC analyses of the reaction products. Lack of activity with O(2) as the oxidant, specificity for C-3 of D-glucose, and active extracellular secretion of the enzyme were used as criteria to differentiate pyranose dehydrogenase from pyranose 2-oxidase (EC 1.1.3.10), known to be produced by numerous wood-rotting fungi. Extracellular pyranose dehydrogenase from Macrolepiota rhacodes was heavily glycosylated. The enzyme was characterized as a 78-kDa flavoprotein under denaturing conditions and a 76-kDa native protein using gel filtration. This enzyme had a maximum extracellular activity of 4.1 U ml(-1) in 39-day liquid cultures. It exhibited broad selectivity for sugar substrates and oxidized D-glucose (K(m)=1.82) exclusively at C-3 to 3-dehydro-D-glucose (D-ribo-hexos-3-ulose), in contrast to pyranose dehydrogenases from Agaricus species, which acted at both C-3 and C-2 of D-glucose. The N-terminal sequence, AVVYRHPDEL, showed significant similarity with that reported for A. bisporus.

Two waves of programmed cell death occur during formation and development of somatic embryos in the gymnosperm, Norway spruce

In the animal life cycle, the earliest manifestations of programmed cell death (PCD) can already be seen during embryogenesis. The aim of this work was to determine if PCD is also involved in the elimination of certain cells during plant embryogenesis. We used a model system of Norway spruce somatic embryogenesis, which represents a multistep developmental pathway with two broad phases. The first phase is represented by proliferating proembryogenic masses (PEMs). The second phase encompasses development of somatic embryos, which arise from PEMs and proceed through the same sequence of stages as described for their zygotic counterparts. Here we demonstrate two successive waves of PCD, which are implicated in the transition from PEMs to somatic embryos and in correct embryonic pattern formation, respectively. The first wave of PCD is responsible for the degradation of PEMs when they give rise to somatic embryos. We show that PCD in PEM cells and embryo formation are closely interlinked processes, both stimulated upon withdrawal or partial depletion of auxins and cytokinins. The second wave of PCD eliminates terminally differentiated embryo-suspensor cells during early embryogeny. During the dismantling phase of PCD, PEM and embryo-suspensor cells exhibit progressive autolysis, resulting in the formation of a large central vacuole. Autolytic degradation of the cytoplasm is accompanied by lobing and budding-like segmentation of the nucleus. Nuclear DNA undergoes fragmentation into both large fragments of about 50 kb and multiples of approximately 180 bp. The tonoplast rupture is delayed until lysis of the cytoplasm and organelles, including the nucleus, is almost complete. The protoplasm then disappears, leaving a cellular corpse represented by only the cell wall. This pathway of cell dismantling suggests overlapping of apoptotic and autophagic types of PCD during somatic embryogenesis in Norway spruce.

Biochemical interactions of conifer seedling roots with Fusarium spp

The importance of root and spore surface molecules in the interactions of Fusarium spp. with conifer roots, and cellular localization of proteins presumed to be involved in host defence, were investigated. For adhesion studies, using a combination of fluorescein isothiocyanate (FITC) labelled lectins and high perfomance liquid chromatography (HPLC), several sugars (pinitol, xylitol, galactose, mannose, and glucose) were detected in root surface mucilage. Both artificial substrata and detached living roots were used to evaluate the significance of selective removal of root or spore surface components on the adhesion process. The spores or roots were pretreated with either periodic acid, pronase E, potassium hydroxide or diethyl ether. Pretreatment of the spores with diethyl ether reduced significantly the level of spore adhesion, which suggests that the adhesive component is either a lipid, or is bound to lipid. Since oxidation of carbohydrate reactive sites with periodic acid on the root surface almost completely abolished the development of germ tubes by adherent spores, it was presumed that some of these periodate-sensitive substances serve as a nutrient source for the fungus. On inoculated roots, F. avenaceum and F. culmorum were significantly pathogenic to both Norway spruce and Scots pine seedlings. Cytochemical labelling of sites of accumulation of host defence molecules within infected root tissues using anti-peroxidase demonstrated increased peroxidase activity in host cell walls. With anti-chitinase and anti-glucanase, gold labelling was found mainly on pathogen hyphal walls.Key words: conifer seedlings, adhesion, Fusarium spp., PR proteins, immunolocalization, lectins.

Pyranose 2-dehydrogenase, a novel sugar oxidoreductase from the basidiomycete fungus Agaricus bisporus

A novel C-2-specific sugar oxidoreductase, tentatively designated as pyranose 2-dehydrogenase, was purified 68-fold to apparent homogeneity (16.4 U/mg protein) from the mycelia of Agaricus bisporus, which expressed maximum activity of the enzyme during idiophasic growth in liquid media. Using 1,4-benzoquinone as an electron acceptor, pyranose 2-dehydrogenase oxidized d-glucose to d-arabino-2-hexosulose (2-dehydroglucose, 2-ketoglucose), which was identified spectroscopically through its N,N-diphenylhydrazone. The enzyme is highly nonspecific. d-,l-Arabinose, d-ribose, d-xylose, d-galactose, and several oligosaccharides and glycopyranosides were all converted to the corresponding 2-aldoketoses (aldosuloses) as indicated by TLC. d-Glucono-1,5-lactone, d-arabino-2-hexosulose, and l-sorbose were also oxidized at significant rates. UV/VIS spectrum of the native enzyme (lambdamax 274, 362, and 465 nm) was consistent with a flavin prosthetic group. In contrast to oligomeric intracellular pyranose 2-oxidase (EC 1.1.3.10), pyranose 2-dehydrogenase is a monomeric glycoprotein (pI 4.2) incapable of reducing O2 to H2O2 (> 5 x 10(4)-fold lower rate using a standard pyranose oxidase assay); pyranose 2-dehydrogenase is actively secreted into the extracellular fluid (up to 0.5 U/ml culture filtrate). The dehydrogenase has a native molecular mass of approximately 79 kDa as determined by gel filtration; its subunit molecular mass is approximately 75 kDa as estimated by SDS-PAGE. Two pH optima of the enzyme were found, one alkaline at pH 9 (phosphate buffer) and the other acidic at pH 4 (acetate buffer). Ag+, Hg2+, Cu2+, and CN- (10 mM) were inhibitory, while 50 mM acetate had an activating effect.

The effect of a single therapeutic dose of cisplatin on GFR in dogs

This study prospectively describes the late effect of a single dose of cisplatin on GFR in tumor-bearing dogs. GFR (measured by quantitative renal scintigraphy), BUN, creatinine, and urine specific gravity values were obtained in 19 tumor-bearing dogs prior to and four weeks after a single dose of cisplatin. Eleven tumor-bearing dogs were given a known non-nephrotoxic anticancer drug, dexniguldipine, as control. No significant differences in pretreatment GFR, serum chemistry, or urinalysis values were observed between cisplatin-treated and control dogs. GFR was significantly decreased four weeks following cisplatin administration. The average percent change in GFR was -13.49% for all cisplatin treated dogs. No significant alterations of BUN, serum creatinine, or urine specific gravity were observed following treatment. In the control group, the average percent change in GFR was +3.98% which was not significantly different from pretreatment values.

Only C-2 specific glucose oxidase activity is expressed in ligninolytic cultures of the white rot fungus Phanerochaete chrysosporium

Two d-glucose-oxidizing enzymes, glucose 1-oxidase (G1O) and pyranose 2-oxidase (P2O, glucose 2-oxidase), have been proposed to play an important role in the ligninolytic system of the white rot fungus Phanerochaete chrysosporium by producing hydrogen peroxide. The possible simultaneous expression and metabolic cooperation of the two oxidases was studied in strains ME-446 (reported as G1O positive) and K-3 (P2O positive) grown in liquid media and under near natural conditions on birch wood blocks. The presence of G1O and P2O in extracts from mycelia and decayed wood was determined by chromatographic, electrophoretic, and immunological methods. Attempts to separate these enzymes and to detect G1O and its reaction product, d-glucono-1,5-lactone, failed. Evidence was obtained only for P2O expression in both strains. Accordingly, P2O, rather than G1O, represents a major source of sugar-derived H2O2 under the culture conditions used.

RFLP markers linked to scald (Rhynchosporium secalis) resistance gene Rh2 in barley

Rhynchosporium secalis is the causal organism of barley scald disease. A number of resistance genes against the fungus are well known; one of them, the single dominant Rh2 resistance gene, has been mapped on the linkage map of barley using RFLP (restriction fragment length polymorphism) markers. The Rh2 gene was located on the distal part of chromosome arm 1S co-segregating with the RFLP marker CDO545 in 85 doubled-haploid progeny plants. The spring barley test population used was a cross between the 6-rowed American spring barley cv Atlas, C.I. 4118, carrying the Rh2 resistance gene, and a Bavarian 2-rowed malting barley cv Steffi, susceptible for R. secalis. The assessment of resistance versus susceptibility was based on artificial infections with a one-spore inoculum in greenhouse tests and with pathotype mixtures in field tests. By testing a pathotype mixture of German origin good resistance was found for the Rh2 gene in the field.

The role of intrarectal ultrasound (IRUS) in staging of rectal cancer and detection of extrarectal pathology

Intrarectal Ultrasound (IRUS) is rapidly becoming an effective tool in the staging of rectal cancer. Twenty-nine consecutive patients with adenocarcinoma of the rectum underwent both CT scanning and IRUS in the preoperative assessment of rectal cancer in an effort to correlate IRUS staging with surgical pathology, correlate tumor staging comparing IRUS with CT scan, and determine incidence of extrarectal pathology by IRUS. Patients were reviewed as to IRUS stage, results of CT scan, TNM stage of extirpated tumor, incidence of genitourinary pathology, and sonographic result of preoperative radiotherapy (RT). The mean age of all patients was 69 years; there were 25 males and four females. Twenty-four patients underwent proctectomy with either low pelvic anastomosis or end stoma; five underwent local surgical therapy. Thirteen patients received preoperative RT. CT scan correlated poorly with IRUS staging of tumors penetrating the muscularis propria. IRUS overstaged 40 per cent, understaged 5 per cent, and correctly staged 55 per cent of patients when compared with pathological specimens. Eleven of the 25 males (44 per cent) had abnormal prostates by IRUS. Five (20%) had further urologic intervention, resulting in two prostatic cancers found. Our data suggests that CT scan staging correlated poorly with IRUS staging. CT poorly determines depth of rectal tumor wall invasion. IRUS correlated well with pathology and understaged 5 per cent of patients before surgery. Genitourinary abnormalities were detected in a significant number of patients. IRUS is an effective modality for preoperative staging of rectal cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Radioimmunodetection of medullary thyroid cancer using a bispecific anti-CEA/anti-indium-DTPA antibody and an indium-111-labeled DTPA dimer

Two-step radioimmunotargeting using a bispecific anti-CEA/anti-in-DTPA monoclonal antibody and an 111In-labeled DTPA dimer (diDTPA-TL) was evaluated nine times in eight patients with medullary thyroid cancer (MTC). Immunoscintigraphy was performed 5 and 24 hr after injection of 111In-diDTPA-TL. For five patients, radioimmunoguided surgery (RIGS) was performed using a hand-held gamma probe (sodium iodine), and a biodistribution study was performed 48 hr (four times) and 24 hr (one time) after injection of 111In-diDTPA-TL. Mean tumor uptake (%ID/kg in tumor) was 39 (range 2.75-139). In these five patients, immunoscintigraphy visualized all known tumors and detected unknown foci (US and CT were negative) in the neck (once) and neck and liver (once). Immunoscintigraphy, performed four times in search of a recurrence, detected unknown localizations in the mediastinum and neck (twice) and was negative twice. There were no false-positives. In three of five patients who had surgery, RIGS localized tumor foci not detected by the surgeon. RIGS failed to detect two small lesions (10 x 10 mm) corresponding to sites of fibrosis and microscopic cancer infiltration. Bispecific anti-CEA/anti-In-DTPA mediated targeting of 111In-diDTPA-TL provided elevated tumor uptake and tumor-to-normal tissue ratios. Radioimmunodetection of small MTC lesions is thus possible even when morphological imaging techniques prove negative.

Pyranosone dehydratase from the basidiomycete Phanerochaete chrysosporium: improved purification, and identification of 6-deoxy-D-glucosone and D-xylosone reaction products

Pyranose oxidase and pyranosone dehydratase (aldos-2-ulose dehydratase), enzymes which convert in coupled reactions D-glucose to beta-pyrone cortalcerone, peaked coincidently during idiophasic growth of Phanerochaete chrysosporium under agitated conditions. The enzymes were purified from mycelial extracts of the fungus and separated from each other by hydrophobic interaction chromatography on Phenyl-Sepharose and Phenyl-Superose. Two pyranosone dehydratase activity peaks, PD I and PD II, were resolved. The major PD I fraction, consisting about 74% of the total dehydratase activity, was further purified by anion exchange chromatography on Mono Q to yield apparently pure enzyme as judged by SDS-PAGE and gel filtration on Superose 12. Isoelectric focusing indicated microheterogeneity of the protein by the presence of at least five protein bands with pI 5.1-5.3. PD II had a pI of 5.75. Overall PD I purification was 60.7-fold with 50% yield. The enzyme acted on several osones (glycosuloses), with the preferred substrate being D-glucosone. D-Xylosone and 6-deoxy-D-glucosone were dehydrated at C-3-C-4 to give the corresponding 5-hydroxy-2,3-dioxoalcanals (4-deoxy-2,3-glycosdiuloses), new enzymatically produced sugar derivatives. The latter labile compounds were trapped as diphenylhydrazine or o-phenylenediamine derivatives and spectroscopically identified. The analogous D-glucosone dehydration product did not accumulate due to its further transformation. pH optimum of PD I activity was 6.0 and its pH stability was optimal at pH 7-11. The enzyme was sensitive to Me2+ chelating agents and some heavy metal ions (Hg2+, Cu2+).