Application of bromodeoxyuridine immunohistochemistry to the rat temporomandibular joint.

To detect S-phase cells in the decalcified paraffin-embedded temporomandibular joint (TMJ) tissues of the rat, bromodeoxyuridine (BrdUrd) immunohistochemistry was performed. Percardiac perfusion of 10% EDTA-2Na Tris buffer accelerated the decalcification. The use of the monoclonal antibody to BrdUrd enabled the visualization of the distribution of S-phase cells. This method is practical in studying cell kinetics and the specific proliferation mode of the TMJ.

Toxicity to beef cattle of sulfur in saline well water: a case study.

A disorder diagnosed as polioencephalomalacia occurred in yearling Hereford heifers, but not in mature cows, within 2 months of exposure to saline well water. The physiological effects of the disorder matched most of the symptoms for bovine polioencephalomalacia. The water contained 3875 mg l-1 total dissolved salts, sulfate and sodium being the dominant ions. Calculated daily sulfur and sodium intakes were near the upper limit of their range for recommended maximum tolerance level. Sulfur toxicity was implicated as the causative agent for the disorder. Differences in effect of waters with similar sulfur contents were attributed to the total dietary sulfur intake by the cattle rather than to the saline water alone. Established guidelines for saline drinking water were deemed not applicable when fodder from saline land is supplied to or grazed by cattle.

Studies on heat treatment for immediate reimplantation of resected bone.

Extracorporeal heat treatment for devitalizing the tumour-infiltrated bone segment without destroying its regenerative potential was investigated for the purpose of immediate reimplantation of the resected bone. Effects of heat treatment on cell viability and bone inductive properties were studied in cultured tumour cells and animal models. Heat treatment at 65 degrees C for 30 to 120 minutes resulted in complete devitalization of cells, preserving osteogenetic properties of the allogenic bone implant in the rabbit. The results of the experiments indicate that this procedure has advantages in devitalizing the resected bone for its immediate reimplantation and justify clinical application. The clinical application of this heat treatment in 3 cases is presented.

Release of bacterial alkaline phosphatase in the rumen of cattle fed a feedlot bloat-provoking diet or a hay diet.

Alkaline phosphatase (APase) was present in the bovine rumen in both cell-free and cell-associated states and levels of the enzyme varied with dietary regime. Reaction product deposition showed that the enzyme was associated with the mixed bacterial population. No enzyme was observed to be associated with protozoa. Trace activity of APase was also detected in the saliva. The presence of large amounts of APase in cell-free rumen fluid of cattle fed fine concentrate feed is believed to be due, in part, to the breakage of bacterial cells that occurs in the rumen.

Frothy feedlot bloat in cattle: production of extracellular polysaccharides and development of viscosity in cultures of Streptococcus bovis.

Streptococcus bovis was cultured in a synthetic medium with three concentrations of sucrose. Initial viscosity of the media was 1.5 centipoise (cp). After incubation for 8 h, the viscosity of the medium with 0.5% sucrose was unchanged, that with 3% sucrose had increased to 8 cp, and that with 6% sucrose to 112 cp. Similar results were found with a rumen fluid medium. A slimy material, responsible for increased viscosity of these cultures, was digested by dextranase. The material appeared as a complex system of intercellular fibers when viewed under the electron microscope after freeze-etching. With proteins and other polymers released from lysed bacteria, this slimy material may contribute directly to increased viscosity and foam formation. In addition to these intercellular fibers, each cell was surrounded by a fibrous capsule that was not digested by dextranase. This capsule stained with lead citrate and uranyl acetate, but not with ruthenium red. The amount of capsular material produced was similar whether the media contained 0.5, 3.0, or 6% sucrose.