Evidence of biogenic greigite (ferrimagnetic Fe3S4) in soil

The occurrence of greigite (Fe₃S₄) in soils is reported for the first time. It forms irregularly-shaped aggregations within plant cells in the Gr₂ horizon of a gley soil developed from colluvial material. Greigite was identified by X-ray diffraction and magnetic measurements and was investigated by optical and transmission electron microscopy. Biogenic formation is proposed, based on the elongated shape of single greigite crystals, and sulphur isotope analyses, which showed a depletion in ³⁴S relative to the soil-water sulphate. The cell-edge length of 0.98639±0.00003 nm is significantly smaller than values reported for sedimentary greigite. The mean coherence length of 27 nm agrees with TEM observations and indicates that the single greigite crystals lie in the superparamagnetic region. However, the fine aggregates show magnetically single-domain behaviour. Greigite is the only carrier of a stable magnetic remanence in the soil profile studied.     

Pasteurella haemolytica A1 and Bovine Respiratory Disease: Pathogenesis

The severe fibrinonecrotic pneumonia associated with pneumonic pasteurellosis usually results from colonization of the lower respiratory tract by Pasteurella haemolytica biotype A, serotype 1(A1). Despite recent research efforts, the authors lack a detailed understanding of the interactions and host response to P. haemolytica in the respiratory tract. The authors hypothesize that management and environmental stress factors or viral infection alters the upper respiratory tract (URT) epithelium allowing P. haemolytica to colonize the epithelium. Once the URT is colonized, large numbers of organisms enter the lung where they interact with alveolar macrophages. Endotoxin, released from the bacteria, crosses the alveolar wall where it activates pulmonary intravascular macrophages, endothelium, neutrophils, lymphocytes, platelets, complement, and Hageman factor leading to complex interactions of cells and mediators. It is the progression of this inflammatory response with neutrophil influx that is ultimately responsible for the pulmonary injury. Leukotoxin is a major virulence factor of P. haemolytica that allows it to survive by destroying phagocytic cells. At subcytolytic concentrations it may also enhance the inflammatory response by activating cells to produce mediators and release reactive oxygen metabolites and proteases.     

Characteristics of cytotoxic cells induced by Toxoplasma lysate antigen in mouse spleen.

Spleen cells from Toxoplasma lysate antigen (TLA)-sensitized BALB/c mice showed the strong cytotoxic activity against both natural killer (NK)-sensitive cells (YAC-1 and RL male-1) and NK-insensitive cells (P-815), when incubated with TLA or recombinant human IL-2 (rhIL-2). The increment of TLA concentration in culture medium increased the cytotoxic activity. Treatment of effector cells; spleen cells from TLA-sensitized mice incubated with TLA, with anti-asialo GM1 or anti-Thy-1 plus complement inhibited the cytotoxic activity of effector cells, whereas treatment with anti-mouse Lyt-2.2 serum plus complement had no effect on the cytotoxic activity. Treatment of spleen cells from TLA-sensitized mice with anti-asialo GM1 and/or anti-Thy-1 plus complement inhibited cytotoxic activities of effector cells. These results suggested that spleen cells sensitized with TLA both in vivo and in vitro were asialo GM1 positive and Thy-1 positive, and the majority of cytotoxic cells induced by TLA were similar to lymphokine-activated killer (LAK) cells induced by IL-2.     

Development of Immune Response to Experimental Bovine Trichophyton vervucosum Infection

Abstract— Cell mediated and humoral immune responses to experimental Trichophyton verrucosum infection were assessed by sequential cutaneous biopsies, antibody assessments and microscopic monitoring of fungal presence. Histopathologic examination showed the accrual of lymphocytes and other inflammatory cells in the dermis of infected sites. Immunoperoxidase staining of frozen sections with monoclonal antibody preparations revealed an influx of macrophages, BoCD4+ and B0CD8+ lymphocytes and γδ T cells from the 5th day to the 33rd day of infection. A moderate influx of B cells was observed. Protein G-colloidal gold staining revealed the presence of immunoglobulins in the dermis and superficial epidermal layers. Trichophyton specific serum antibodies appeared between days 33 and 55. Microscopic assessment of infected tissues revealed an increase in T, verrucosum elements (mycelium and ectothrix spores) from days 19 to 55. Fungal elements in infected areas did not decrease until after both humoral and cell mediated elements of the immune response were established. These responses imply a combination of cell mediated and humoral events were associated with T. verrucosum immunity and clearance in the calf. Résumé— Le réponse immunitaire humorale et cellulaire a une infection expérimentale àT. verrucosum a été appréciée par des biospsies cutanées successives, des dosages d'anticorps et la recherche microscopique de champignons. L'examen histopathologique a montré un afflux de lymphocytes et d'autres cellules inflammatoires dane le derme des sites infectés. Les marquages en immunopéroxydase par un anticorps monoclonal de coupes congelées a montré un influx de macrophages, lymphocytes BoCD4+ et BoCD8+ et des cellules T γδ, du 5e au 33e jour de l'infection. Un marquage par une protéine G—or colloidal a révélé d'immunogolglobulines dans le derme et les couches supéerficielles de l'épiderme. Les anticorps spécifiques de Trichophyton sont apparus entre 33 et 55 jours. L'examen microscopique des tissus infectés a révélé une augmentation du nombre d'éléments de T. verrucosum (mycelium et spores ectothrix) du 19e au 55e jours. Les éléments fongiques dans les zones infectées n'ont pas diminué avant que les réponses humorales et cellulaires ne solent établies. Ces résponses impliquent qu'une coopération des réponses humorales et cellulaires étaient associées dans l'immunité et la défense contre T. verrucosum. Zusammenfassung— Die zellvermittelten und humoralen Immunantworten auf die experimentelle Infektion mit T. verrucosum wurden durch eine Serie von Hautbiopsien, Antikörperuntersuchungen und mikroskopischer Untersuchung auf das Vorhandensein von Pilzen ausgewertet. Die histopathologische Untersuchung zeigte eine Ansammlung von Lymphozyten und anderen Entzündungszellen in der Dermis der infizierten Stellen. Die Immunperoxidasefärbung der Gefrierschnitte mit monoklonalen Antikörperzubereitungen zeigte einen Influx von Makrophagen, BoCd4-und BoCD8-Lymphozyten und gamma-delta-T-Zellen vom 5. bis zum 33. Tag der Infektion. Es wurde auch ein mäßiger Influx von B-Zellen beobachtet. Die Protein-G-kolloidale Goldfärbung zeigte die Anwesenheit von Immunglobulinen in der Dermis und den oberflächlichen epidermalen Schichten. Trichophyton-spezifische Serumantikörper traten zwischen Tag 33 und 55 auf. Die mikroskopische Untersuchung infizierter Gewebe zeigte eine Zunahme von T. verrucosum-Bestandteilen (Myzel und exktothrixe Sporen) vom Tag 19 bis 55. Pilzteile in infizierten Bereichen verminderten sich weder, nachdem humorale, noch nachdem zellvermittelte Elemente der Immunantwort auftraten. Diese Reaktionen deuten an, daß eine Kombination von zellvermittelten und humoralen Vorgängen im Zusammenhang mit T. verrucosum-Immumtät und Abheilung beim Kalb vorliegt. Resumen Por medio de biposias cutáneas secuenciales, medida de anticuerpos y exámen microscópico de presencia de hongos, se estudió la respuesta inmunitaria de tipo humoral y celular producida por la infección experimental con T. verrucosum. El exámen histopatológico reveló la presencia de agregación de linfocitos y otras células inflamatorias procedentes de la dermis de los puntos infectados. La tintura por medio de inmunoperoxidasa de las secciones congeladas, con preparaciones monoclonales de anticuerpos, demostró un aflujo de macrófagos BoCD4 + y BoCD8 + linfocitos y linfocitos, Tαδ, desde el quinto hasta el día 33 la infección. También se observó un aflugo moderado de linfocitos B. La tintura aúrica de proteina coloidal G reveló la presencia de inmunoglobulinas en al dermis y capas superficiales de la epidermis. Los anticuerpos específicos para la especie Trichophyton aparecieron entre los días 33 y 55. El exámen microscópico de los tejidos afectados demostró un incremento, de los elementos füngicos T. verrucosum (micelio y esporas exótricas) desde los días 19 al 55. Los elementos fúngicos en áreas infectadas no disminuyeron hasta después del establecimiento de ambos tipos de respuesta inmunitaria, humoral y celular. Estas respuestas implican que la combinación de ciertos fenómenos de inmunidad celular y humoral, están relacionados con la desaparición y la inmunidad de la infección producia por T. verrucosum en el ternero.     

Oxidative damage to the membrane of canine erythrocytes with inherited high Na, K-ATPase activity.

Oxidative damage to the membrane in canine erythrocytes with inherited high Na, K-ATPase activity (HK cells) was compared with that in normal canine cells (LK cells). When 30 mM beta-acetylphenylhydrazine (APH) was applied to HK and LK cells, lipid peroxidation and hemoglobin denaturation occurred. Lipid peroxidation determined from malondialdehyde (MDA) formation was significantly lower in HK than in LK cells so far as endogenous glutathione (GSH) concentration was maintained at appropriate levels. With the depletion of GSH, MDA formation was accelerated and difference between HK and LK cells was not significant. Denatured hemoglobin bound to the membrane protein was less in HK than in LK cells. During incubation with APH, osmotic fragility increased markedly in LK cells, while HK cells showed very little change. The amounts of total lipid, total and free cholesterol, glycolipid, phospholipid and fatty acids were essentially the same in both cell types. Fatty acid compositions showed very small differences. The membrane of HK cells thus appear to have greater protection against oxidative damage induced by APH, owing to the presence of excess GSH in HK cells. The capability of HK cells to withstand oxidative damage would not be due to differences in membrane lipid compositions.     

Prevention of estrus in the queen with chlormadinone acetate administered orally.

The possibility of estrus prevention in the queen by the oral administration of chlormadinone acetate was examined. The animals used were 29 mature and 15 immature queens. For 16 mature females, 4-12.5 mg was given daily by mouth for 7 days every 3 months. Ten of the 16 queens given this treatment came into estrus within 4 months of the first treatment. For 28 females including the immature, 2-12.5 mg was given once a week throughout the experiment. This treatment prevented estrous activity for at least 1 year. In the queens in this study, the side effects were not observed excepting an increase in body weight during treatment. Our results showed that oral administration of this drug weekly is safe and reliable for long-range prevention of estrus in queens.     

Cumulus Oophorus Expansion of Bovine Oocytes Cultured in vitro: A SEM and TEM Study

Bovine cumulus-oocyte complexes (COCs) were aspirated from antral follicles (3–6 mm in diameter). COCs with a compact multilayered cumulus investment were cultured for 9, 13 and 24 hours, respectively, and processed for scanning or transmission electron microscopy after different periods of culture including a 0 hour control group. In all 0 hour control COCs initial formation of cumulus cell projections, blebs and microvilli were observed. The start of cumulus-oocyte disconnection in cattle was observed after 9 hours of in vitro culture. These connections were almost completely discrupted after 13 hours, when a continuous production of extracellular matrix was observed. The full expansion of corona radiata cells was not observed even after 24 hours. Some cumulus oophorus cells were bound together with junctions of the zonula adherens type after 24 hours when extracellular matrix was found only in deeper layers. The full expansion of corona radiata cells was not the prerequisite for disconnection of cumulus-oocyte complex. Inhalt: Kumulus oophorus Expansion von in vitro kultivierten Rinderoozyten: Eine SEM und TEM Untersuchung Kumulus-Oozyten-Komplexe (COC) von Rindern wurden aus antralen Follikeln aspiriert (Durchmesser 3–6 mm). COC's mit kompakten mehrschichtigen Kumulus wurden für 9, 13 und 24 Stunden kultiviert und für die Scanner- oder Transmissionselektronenmikroskopie vorbereitet. Verschiedene Kulturzeiten incl. einer 0-Stundengruppe als Kontrolle wurden untersucht. In allen Kontroll COC's wurden beginnende Formationen yon Kumuluszellprojektionen, Bläschen und Mikrovilli beobachtet. Nach 9-stündiger in vitro Kultur begann die Lösung zwischen Kumulus und Oozyte. Die Verbindungen waren nach 13 Stunden vollständig unterbrochen, wobei eine kontinuierliche Produktion extrazellulärer Matrix beobachtet wurde. Eine vollständige Expansion der Corona radiata Zellen wurde auch nicht nach 24 Stunden beobachtet. Nach 24 Stunden waren einige Cumulus Oophorus Zellen über Verbindungen des Zonula adherens Typs verknüpft, wobei extrazelluläre Matrix nur in den tieferen Zellschichten gefunden wurde. Eine vollständige Kumulusexpansion ist keine Voraussetzung für die Auflösung des Kumulus-Oozyten-Komplexes.     

The Effect of Lead and Zinc on Plant Growth and Chlorophyll Content of Holcus lanatus L.

Root length of Holcus lanatus L. declined rapidly with increasing lead and zinc concentrations in nutrient solution. In all used Pb and Zn concentrations root growth of genotypes coming from a Pb-Zn mine area, was greater than that of the control, suggesting that these genotypes evolved tolerance to Pb and Zn.
Negative correlation was also observed between chlorophyll content and increased heavy metal concentrations. The greater chlorophyll content found in tolerant genotypes, in different Pb and Zn concentrations, in comparison with the control, could be served to distinguish tolerant and non-tolerant genotypes.     

Use of autogenous cancellous bone graft for treatment of osteolytic defects in the phalanges of three cattle.

Osteolytic defects were detected radiographically in the distal sesamoid bone of a 16-month-old Bralers heifer, in the middle phalanx of a 14-month-old American Gray Brahman bull, and in the distal phalanx of a 3-year-old American Gray Brahman bull. The articular cartilage was damaged in each animal because of osteolysis or pathologic fracture. After each animal was anesthetized and positioned in lateral recumbency, the lesions were curetted and packed with cancellous bone harvested from the same animal's tuber coxae. Basic postoperative management involved stall rest and immobilization of the graft site with a fiberglass cast (42 to 79 days), after which a support bandage was used for approximately 2 weeks. Recurrence of lameness has not been observed in these animals for 60 months, 58 months, and 21 months, respectively. These cases exemplify the benefit of using an autogenous cancellous bone graft for treatment of severe osteolysis of a digit in cattle.