Bacterial biodegradation of extractives and patterns of bordered pit membrane attack in pine wood.

Wood extractives, commonly referred to as pitch, cause major problems in the manufacturing of pulp and paper. Treatment of nonsterile southern yellow pine chips for 14 days with Pseudomonas fluorescens, Pseudomonas sp., Xanthomonas campestris, and Serratia marcescens reduced wood extractives by as much as 40%. Control treatments receiving only water lost 11% of extractives due to the growth of naturally occurring microorganisms. Control treatments were visually discolored after the 14-day incubation, whereas bacterium-treated wood chips were free of dark staining. Investigations using P. fluorescens NRRL B21432 showed that all individual resin and fatty acid components of the pine wood extractives were substantially reduced. Micromorphological observations showed that bacteria were able to colonize resin canals, ray parenchyma cells, and tracheids. Tracheid pit membranes within bordered pit chambers were degraded after treatment with P. fluorescens NRRL B21432. P. fluorescens and the other bacteria tested appear to have the potential for biological processing to substantially reduce wood extractives in pine wood chips prior to the paper making process so that problems associated with pitch in pulp mills can be controlled.

Morphologic changes in the lungs of cats experimentally infected with Dirofilaria immitis. Response to aspirin.

The morphologic response of the pulmonary arteries and lungs in cats was studied after a five month heartworm infection produced by transplantation of four adult heartworms/cat. One group of seven heartworm infected cats was not treated, another group of seven cats was treated with 97.5 mg of aspirin given twice a week, and the third group of six cats was given aspirin at a sufficient dosage to block in vitro platelet aggregation throughout the study. A fourth group of eight noninfected cats served as controls. Five months after heartworm infection, the cats were euthanized and the lungs perfusion fixed for light microscopy and scanning electron microscopy of the pulmonary arterial surfaces. All cats in the three heartworm-infected groups had live heartworms and the typical pulmonary arterial changes of heartworm disease at necropsy. The arterial surfaces, as viewed with scanning electron microscopy, had villus proliferations that were more numerous and exuberant than similar infections in dogs. Mean percentage of arterial surface involvement with villus proliferation of the nontreated heartworm infected cats was 67.3%; the aspirin treated cats, 73.8%; and the adjusted aspirin treated cats, 75.9%. The villi were myointimal proliferations in the small and medium-sized arteries. The more elastic arteries had a predominance of fibromuscular proliferation. All heartworm infected cats had arterial muscular hypertrophy of the small arteries, in contrast to only three of eight of the nonheartworm infected cats. The caudal lobar arteries were frequently obstructed with either villus proliferation, thrombi, and/or dead heartworms. The muscular arteries had branches with marked dilation, a condition associated with pulmonary hypertension in man. However, only three cats, one in each group, had pulmonary hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracranial schwannoma in a horse.

A case of intracranial schwannoma is described in a young horse. Clinical signs developed slowly and were suggestive of a lesion involving the left cerebrum. The filly exhibited a change in mentation, and circled to the left. Visual impairment and decreased facial sensation were noted on the right side. A solitary schwannoma which compressed the left cerebrum was found at necropsy.

Detection of lignin peroxidase and xylanase by immunocytochemical labeling in wood decayed by basidiomycetes.

The white rot fungi used in this study caused two different forms of degradation. Phanerochaete chrysosporium, strain BKM-F-1767, and Phellinus pini caused a preferential removal of lignin from birch wood, whereas Trametes (Coriolus) versicolor caused a nonselective attack of all cell wall components. Use of polyclonal antisera to H8 lignin peroxidase and monoclonal antisera to H2 lignin peroxidase followed by immunogold labeling with protein A-gold or protein G-gold, respectively, showed lignin peroxidase extra-and intracellularly to fungal hyphae and within the delignified cell walls after 12 weeks of laboratory decay. Lignin peroxidase was localized at sites within the cell wall where electron-dense areas of the lignified cell wall layers remained. In wood decayed by Trametes versicolor, lignin peroxidase was located primarily along the surface of eroded cell walls. No lignin peroxidase was evident in brown-rotted wood, but slight labeling occurred within hyphal cells. Use of polyclonal antisera to xylanase followed by immunogold labeling showed intense labeling on fungal hyphae and surrounding slime layers and within the woody cell wall, where evidence of degradation was apparent. Colloidal-gold-labeled xylanase was prevalent in wood decayed by all fungi used in this study. Areas of the wood with early stages of cell wall decay had the greatest concentration of gold particles, while little labeling occurred in cells in advanced stages of decay by brown or white rot fungi.

Effects of D,L-2-difluoromethylornithine and indomethacin on mammary tumor promotion in rats fed high n-3 and/or n-6 fat diets.

Virgin female Sprague-Dawley rats (50 days of age) were administered a single intragastric 10-mg dose of 7,12-dimethylbenz(a)anthracene (DMBA). Twenty-one days later they were placed on diets containing either 20% corn oil (CO), 15% menhaden oil plus 5% corn oil (MO + CO), 20% CO plus 0.5% w/w of the irreversible ornithine decarboxylase inhibitor, D,L-2-difluoromethylornithine (CO + DFMO), 20% CO plus 0.004% w/w of the cyclooxygenase inhibitor indomethacin (CO + INDO), 20% CO + 0.004% INDO + 0.5% DFMO (CO + INDO + DFMO), or 15% MO + 5% CO + 0.5% DFMO (MO + CO + DFMO). The incidence of DMBA-induced mammary tumors was significantly reduced in rats fed diets containing DFMO but not in rats fed the diet containing indomethacin. Incidences of mammary tumors at 16 weeks post-DMBA were 86% in rats fed the CO diet, 83% in rats ingesting the diet containing CO + INDO, 28% in rats fed CO + DFMO, 32% in rats fed diet containing CO + INDO + DFMO, 59% in rats fed the MO + CO diet, and 24% in rats fed the MO + CO + DFMO diet. The average number of tumors and tumor burden per tumor-bearing rat were reduced and tumor latency was increased in all rats fed diets containing DFMO. Body weight gain, but not food intake, of rats fed the 20% fat + 0.5% DFMO diets was significantly less than in rats fed the 20% fat diets. Prostaglandin E and leukotriene (LTB4) syntheses, ODC activity and mammary tumorigenesis were significantly inhibited by feeding the diet containing menhaden oil or by adding 0.5% DFMO to any of the high fat diets. Feeding a 20% CO diet containing 0.004% INDO significantly reduced prostaglandin synthesis and ODC activity and increased LTB4 synthesis of mammary tumors but did not inhibit mammary tumorigenesis. This study suggests that the 5-lipoxygenase product LTB4 may be involved in mammary tumor production. Whereas a decrease in LTB4 appears to be associated with a decrease in tumorigenesis, an increase (as seen in the indomethacin group) was not associated with any change in the tumorigenic response.

Tracheal carcinoma in a dog.

Tracheal carcinoma was diagnosed in a 10-year-old male Spitz dog suffering from dyspnoea. The tumour was poorly differentiated, but desmosomes were seen by transmission electron microscopy.

Sequential study of lesion development in experimental haemophilus pleuropneumonia.

Recently weaned pigs were infected aerogenically with Haemophilus (Actinobacillus) pleuropneumoniae, serotype 5. At three, six, 12, and 18 hours and one, two, four and seven days after exposure to haemophili a pair of animals were killed and necropsied. Pulmonary oedema with multifocal petechial haemorrhages and a diffuse neutrophilic bronchiolitis and alveolitis were observed at three and six hours after infection. Focal areas of coagulative necrosis developed in areas of intense suppuration at 12 and 18 hours after infection. At one and two days after infection, necrotic areas were surrounded by dense bands of degenerating leucocytes and contained unidentifiable round and elongated cells characteristic of this disease. In subacute lesions a thick layer of granulation tissue formed around the outer margin of developing abscesses. Most of the round and elongated cells in alveolar exudates could not be identified by enzyme histochemistry or electron microscopic examination. Neutrophils in various stages of degeneration and deterioration provided strong evidence that some of the cells were of this type. These findings suggest that neutrophils may play an early and significant role in development of lesions.

Acute inflammatory effects of intratracheally instilled Escherichia coli endotoxin and sonicated suspension of Haemophilus pleuropneumoniae in swine.

A single bolus of either Escherichia coli endotoxin, sonicated suspension of Haemophilus pleuropneumoniae, or pyrogen-free normal saline was intratracheally instilled in six week old specific-pathogen-free pigs. Pigs exposed to E. coli endotoxin developed fever, leukopenia followed by leukocytosis, and endotoxemia. Leukocytosis was the only clinical abnormality noted in pigs receiving the sonicated suspension of H. pleuropneumoniae. At one day postexposure, focal areas of atelectasis and consolidation were observed in the caudal lung lobes of animals receiving either E. coli endotoxin or the sonicated suspension of H. pleuropneumoniae. Lesions were characterized by a neutrophilic bronchitis and bronchiolitis with alveolitis in the surrounding tissue. Increased numbers of alveolar macrophages and evidence of phagocytosis were observed by light and electron microscopy. No clinical abnormalities or lesions were observed in animals receiving normal saline. Lesions typical of acute porcine Haemophilus pleuropneumonia were not produced by either E. coli endotoxin or sonicated suspension of H. pleuropneumoniae, indicating that multiple virulence factors are probably involved in lesion development.

Role of Veratryl Alcohol in Regulating Ligninase Activity in Phanerochaete chrysosporium.

Ligninase activity in Phanerochaete chrysosporium is stimulated by incubating cultures with various substrates for the enzyme, including veratryl (3,4-dimethoxybenzyl) alcohol, which is a secondary metabolite of this fungus. This study was designed to provide insight into the mechanism involved in this stimulation. Ligninase activity increased 2 to 4 h after the addition of exogenous veratryl alcohol to ligninolytic cultures. This increase was prevented by inhibitors of protein synthesis. Analysis of the extracellular proteins by high-performance anion-exchange liquid chromatography revealed increases in the amounts of some, but not all, ligninase species. The normal rapid decrease in ligninase activity in aging cultures was not prevented or retarded by veratryl alcohol, indicating that veratryl alcohol does not increase ligninase activity by protecting extant enzyme. We conclude that veratryl alcohol probably functions via an induction type of mechanism, affecting only certain ligninase species. Results with an isolated lignin indicate that lignin (or its biodegradation products) functions in the same way that veratryl alcohol does.

Increased pulmonary clearance of Serratia marcescens in calves given intravenous Freund's complete adjuvant.

Lung and alveolar macrophage studies were conducted following experimental immunostimulation of calves with Freund's complete adjuvant (FCA). Intravenous administration of FCA to calves 35 days before aerosol exposure to serratia marcescens resulted in a 53.1% reduction in the 2-hour pulmonary mean percent retention of the organism when compared to control calves. FCA treatment increased alveolar macrophage concentration (cells/g lung) by 30.9%. Lymphoid and granulomatous responses were increased in the lungs of treated calves.

An ultrastructural study of bronchiolar lesions in rats induced by 4-ipomeanol, a product from mold-damaged sweet potatoes.

Repeated intraperitoneal injections of 4-ipomeanol in rats resulted in extensive degeneration and necrosis of nonciliated (Clara) bronchiolar epithelial cells. Subsequently there was necrosis and detachment of ciliated cells from the bronchiolar basal lamina. The remaining nonciliated cells divided and differentiated into ciliated epithelial cells and mature Clara cells. The ability of Clara cells to metabolize certain xenobiotics suggests that they may play an important role in the pathogenesis of pulmonary disease and neoplasia.

Globin expression in Rous sarcoma virus-transformed quail myoblasts.

Viral transformation affects certain developmental processes by blocking the differentiation of cells such as primitive muscle cells (myoblasts) or primitive red blood cells (erythroblasts). Embryonic quail myoblasts, transformed with a temperature-sensitive (ts) mutant of Rous sarcoma virus (RSV) are blocked in differentiation at the viral permissive temperature of 35 degrees C, but fuse to form myotubes at the nonpermissive temperature of 41 degrees C. We have shown that viral transformation of quail myoblasts also causes transcription of non-muscle-specific genes, ie, globins at 35 degrees C that are not observed in uninfected myoblasts or myotubes. Transformed myoblasts shifted to 41 degrees C for 5 days still contain these globin transcripts. Both alpha-like and beta-like globins are expressed.

Tissue residues from feeding pentachloronitrobenzene (quintozene) to White Leghorn chickens.

One-day-old White Leghorn chicks were fed graded levels (0, 10, 50, 100 and 1,000 ppm) of pentachloronitrobenzene (PCNB; quintozene) up to 8 weeks. Each treatment group consisted of 90 randomly selected birds (2 replications of 45 birds each). Body weight gains were significantly lower at the 1,000-ppm treatment level. Histopathologic examination of brain, liver, pancreas, small intestine, gizzard, spleen, kidney, lung, and heart failed to reveal lesions in either control or treated groups. Bioaccumulation of PCNB or its metabolites (pentachloroaniline and pentachlorophenylmethylsulfide) in tissues only occurred in trace or very low concentrations. However, trace contaminating of PCNB, eg, hexachlorobenzene (HCB) and pentachlorobenzene (PCB) accumulated in tissues to a significant degree. Tetrachloronitrobenzene, another contaminant of PCNB, was found in only the adipose and cardiac tissues following the feeding of 1,000 ppm PCNB. Storage of PCNB, HCB, and PCB in adipose and other tissues was linearly related to the amount of PCNB in the ration.

Gallstone obstruction of duodenal cap (Bouveret's syndrome) diagnosed by endoscopy.

A patient presenting with signs and symptoms of gastric outlet obstruction and acute oliguric renal failure underwent early endoscopic examination. A large gallstone was seen obstructing the duodenal cap. Bouveret's syndrome and the role of endoscopy in early diagnosis are discussed.

The accumulation and elimination of tissue residues after feeding pentachloronitrobenzene to White Leghorn cockerels.

Day-old White Leghorn cockerels were fed graded levels (10, 50, 100, and 1000 ppm) of pentachloronitrobenzene (PCNB) containing pentachlorobenzene (PCB), tetrachloronitrobenzene (TCNB), and hexachlorobenzene (HCB) at trace contaminants, for 12 weeks. Bioaccumulation of PCNB and its metabolites in tissues does not appear to occur to any major extent. The contaminants of PCNB, HCB, and PCB were found to accumulate to a greater degree in adipose tissue than does PCNB itself. TCNB was also detected in adipose tissue and in trace amounts in other tissues. PCNB accumulated to the highest concentration in body fat followed by gizzard and kidney. Only traces of PCNB were found in heart, liver, leg, and heart muscle. Metabolites, pentachloroaniline (PCA), and pentachlorphenylmethylsulfide (PCMS) were found in only trace quantities following the feeding of 1000 ppm PCNB. Half-life values for the depletion of the contaminants of PCNB, PCB, and HCB were determined in adipose tissue of cockerels; values as high as 53 and 95 days were found for PCB and HCB, respectively.

The anatomy and physiology of the bovine respiratory system relating to pulmonary disease.

Bovine respiratory anatomy and physiology were reviewed and considered in relationship to the pathogenesis of pulmonary disease. Factors which may predispose cattle to respiratory disease included a small physiological gaseous exchange capacity, greater basal ventilatory activity, and greater anatomical compartmentalization of the lung as compared with other mammals, a low level and atypical bioactivity of bovine lysozyme, and low numbers of macrophages within the alveolar lumen.