Effective deacetylation of chitin under conditions of 15 psi/121 degrees C

Deacetylation of chitin under autoclaving conditions (15 psi/121 degrees C) was evaluated for the preparation of chitosan under different NaOH concentrations and reaction times. Deacetylation was effectively achieved by treatment of chitin under elevated temperature and pressure with 45% NaOH for 30 min and a solids/solvent ratio of 1:15. Treated chitosan showed similar nitrogen content (7.42%), degree of deacetylation (90.4%), and molecular mass (1560 kDa) but significantly higher viscosity values (2025 cP) compared with those (7.40%, 87.6%, 1304 kDa, and 143 cP, respectively) of a commercial chitosan. Reduction of the solids/solvent ratio from 1:15 to 1:10 did not affect degree of deacetylation, viscosity, and molecular mass of chitosan.     

Antioxidant and antiproliferative activities of strawberries

Strawberries contain high levels of antioxidants, which have been correlated with a decreased risk of chronic disease. To more fully characterize the antioxidant profiles and possible associated health benefits of this fruit, the total free and bound phenolic, total flavonoid, and total anthocyanin contents of eight strawberry cultivars (Earliglow, Annapolis, Evangeline, Allstar, Sable, Sparkle, Jewel, and Mesabi) were measured. Cultivar effects on phenolic contents were compared with antioxidant capacities, as measured by the total oxyradical scavenging capacity (TOSC) assay, and to antiproliferative activities, as measured by inhibition of HepG(2) human liver cancer cell proliferation in vitro. Free phenolic contents differed by 65% between the highest (Earliglow) and the lowest (Allstar) ranked cultivars. The water soluble bound and ethyl acetate soluble bound phenolic contents averaged 5% of the total phenolic content of the cultivars. The total flavonoid content of Annapolis was 2-fold higher than that of Allstar, which had the lowest content. The anthocyanin content of the highest ranked cultivar, Evangeline, was more than double that of the lowest ranked cultivar, Allstar. Overall, free phenolic content was weakly correlated with total antioxidant activity, and flavonoid and anthocyanin content did not correlate with total antioxidant activity. The proliferation of HepG(2) human liver cancer cells was significantly inhibited in a dose-dependent manner after exposure to all strawberry cultivar extracts, with Earliglow exhibiting the highest antiproliferative activity and Annapolis exhibiting the lowest. No relationship was found between antiproliferative activity and antioxidant content.     

Control technology for coal-fired combustion in northeastern U.S.

The status of air pollution control technology for coal fired industrial and power plant boilers has been surveyed. Lime and limestone based scrubbers are capable of removing as much as 93% of flue gas SO₂ at facilities supplying 800 MW power. A sludge containing SO _x ions must be discarded in the process, usually requiring landfill or a settling pond. The Wellman-Lord, thiosorbic, and citrate processes are capable of producing salable products instead of the sludge. They are successful (85 to 90% removal) on demonstration-scale units. The Wellman-Lord process is currently being tested on large-scale coal fired units. Electrostatic precipitators, the mahor control device for removing particulates, can eliminate 99.5% of the fine particles. Fabric filtration can remove 99.9% and is more efficient in the 0.2 to 2μm size range than ESPs. Utilization of fabric filters is expected to increase significantly from its present 5% of the particulate removal market. Nitrogen oxide concentrations in coal fired systems are usually reduced by modification of the combustion system. No significant NO _x reduction on full-scale boilers has yet been reported, but demonstrations are planned over the next few years. Various process capital and annualized costs are reported for SO₂ and particulate removal systems. The status of fluidized bed combustion, fuel desulfurization, conversion of coal to gaseous and liquid fuels, and flue gas denitrification is also discussed. Part A deals with S emission; Part B with NO _x , particulates, and combined systems.     

Varietal differences in phenolic content and antioxidant and antiproliferative activities of onions

Epidemiological studies have indicated that the consumption of fruits and vegetables is associated with a reduced risk for the development of chronic diseases, such as cardiovascular disease and cancer. Phytochemicals, including phenolics and flavonoids, are suggested to be the major bioactive compounds contributing to the health benefits of fruits and vegetables. Onions are a major source of dietary flavonoids; however, there may exist varietal differences in composition, concentration, and beneficial activities. To characterize these differences, shallots and 10 onion (Allium cepa L.) varieties commonly available in the United States (Western Yellow, Northern Red, New York Bold, Western White, Peruvian Sweet, Empire Sweet, Mexico, Texas 1015, Imperial Valley Sweet, and Vidalia) were evaluated for total phenolic and flavonoid contents and antioxidant and antiproliferative activities. Shallots contained the highest total phenolic content (114.7 +/- 10.0 mg/100 g of sample) among the varieties tested, with a 6-fold difference observed when compared to the variety with the lowest phenolic content (Vidalia, p < 0.05). Western Yellow onion variety exhibited the highest total flavonoid content (69.2 +/- 3.7 mg/100 g of onion) of the varieties tested, with an 11-fold difference when compared to the variety with the lowest flavonoid content (Western White, p < 0.05). Shallots exhibited the highest total antioxidant activity (45.5 +/- 2.1 micromol of vitamin C equiv/g of onion), followed by Western Yellow, New York Bold, Northern Red, Mexico, Empire Sweet, Western White, Peruvian Sweet, Texas 1015, Imperial Valley Sweet, and Vidalia. For all varieties, both total phenolic and flavonoid contents were strongly correlated with total antioxidant activity (R (2) = 0.9668, p < 0.05; and R (2) = 0.7033, p < 0.05, respectively). The proliferation of HepG(2) and Caco-2 cells was significantly inhibited in a dose-dependent fashion after exposure to the Western Yellow, shallots, New York Bold, and Northern Red extracts, with Western Yellow, shallots, and New York Bold exhibiting the highest antiproliferative activity against HepG(2) cells and New York Bold and Western Yellow exhibiting the highest antiproliferative activity against Caco-2 cells. However, the varieties of Western White, Peruvian Sweet, Empire Sweet, Mexico, Texas 1015, Imperial Valley Sweet, and Vidalia demonstrated weak antiproliferative activity against both HepG(2) and Caco-2 cells. These results may influence consumers toward purchasing onion varieties exhibiting greater potential health benefits and may significantly affect future breeding efforts to enhance onion nutritional qualities.     

Hormonal changes in sows after induced porcine parvovirus infection in early pregnancy

Hormonal changes, lesions, and virus isolation studies were determined in sows after uterine artery inoculation with porcine parvovirus [( PPV], strain NADL-8) in early pregnancy. Two sows were given PPV on days 14 or 16 and were euthanatized and necropsied on day 35 after twice daily plasma collection for hormone measurement. Parvovirus was given to 4 sows on day 14 and to 4 sows on day 21 with 5 times daily plasma samples collected for 1 week. Sows were examined on days 21 and 28, respectively. Four control sows in each group on days 14 and 21 were given a placebo injection and were similarly studied. All embryos in all but 1 sow given PPV were in various stages of resorption at necropsy. Normal embryos were present in all control sows. Estrone sulfate values increased logarithmically, progesterone values remained stable, and concentrations of 13, 14-dihydro-15-keto-prostaglandin (PG) F2 alpha (PGFM), a PGF2 alpha metabolite, were less than 200 ng/ml for sows given a placebo. In contrast, sows with resorbing embryos did not have an increase in estrone sulfate values. A decrease in plasma progesterone values occurred in 9 of 10 sows inoculated with PPV; this decrease was accompanied by greater than or equal to 1 marked increase in PGFM concentrations. Quantitative assessment of the uterus revealed significantly greater cytoplasmic density in endometrial and glandular cell (P less than 0.01), a greater glandular epithelium height (P less than 0.05), and twice the number of glands (P less than 0.05) in control sows, compared with values in sows inoculated with PPV.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation Of An Additive Solution For Preservation Of Canine Red Blood Cells

The effect of an additive preservative solution on canine red blood cell posttransfusion viability (PTV) and on selected canine red blood cell biochemical parameters was studied. One unit (450 mL) of blood was collected from 6 clinically normal dogs into the anticoagulant citrate phosphate dextrose, centrifuged, and the plasma removed. The red blood cells were then suspended in 100 mL of a saline, adenine, dextrose, and mannitol solution and stored at 4°C. Aliquots were removed for study at 1, 10, 20, 30, 37, and 44 days. The 24-hour PTV of autologous red blood cells was determined using a sodium chromate (⁶¹Cr) label. Red blood cell concentrations of 2,3-diphosphoglycerate (2,3-DPG), adenosine-5'-triphosphate (ATP), and pH were also determined. Canine red blood cell PTV, pH, ATP, and 2,3-DPG concentrations decreased during storage ( P < .05). The PTV decreased from 94% using day 1 red blood cells to 80% and 75% using day 37 and day 44 red blood cells, respectively ( P < .05). Although the mean PTV of the day 44 stored units equaled the Food and Drug Administration (FDA) minimum standard for human red blood cells, the PTV was substandard in 75% of the day 44 units. The FDA standard was exceeded in 83% of the day 37 units. It was concluded that 37-day-old canine red blood cells preserved with a saline, adenine, dextrose, and mannitol solution are of acceptable quality for transfusion.     

Binding of 125I-labeled endotoxin to bovine, canine, and equine platelets and endotoxin-induced agglutination of canine platelets

Endotoxin from Escherichia coli O127:B8, Salmonella abortus-equi and S minnesota induced clumping of some canine platelets (PLT) at a final endotoxin concentration of 1 microgram/ml. Endotoxin-induced clumping of canine PLT was independent of PLT energy-requiring processes, because clumping was observed with canine PLT incubated with 2-deoxy-D-glucose and antimycin A. The PLT responded to adenosine diphosphate before, but not after, incubation with the metabolic inhibitors. Endotoxin induced a slight and inconsistant clumping of bovine and equine PLT at high (mg/ml) endotoxin concentration. High-affinity binding sites could not be demonstrated on canine, bovine, and equine PLT, using 125I-labeled E coli O127:B8 endotoxin. Nonspecific binding was observed and appeared to be due primarily to an extraneous coat on the PLT surface that was removed by gel filtration. The endotoxin that was bound to PLT did not appear to modify PLT function. An attempt to identify plasma proteins that bound physiologically relevant amounts of endotoxin was not successful. The significance of the endotoxin-induced clumping or lack of it on the pathophysiology of endotoxemia is discussed.     

Staphylococcosis of turkeys. 1. Portal of entry and tissue colonization

Staphylococcus aureus and various coagulase-negative staphylococci were isolated from turkeys with staphylococcosis. Virulent S. aureus adhered well (averaged more than 100 bacteria per tissue cell) in vitro to cells from tissues of the respiratory tract but did not adhere well (averaged fewer than 12 bacteria per tissue cell) to cells from tissues of the alimentary tract. Some avirulent coagulase-negative staphylococci also adhered well to cells from the respiratory tissues. Lungs and livers of turkeys became colonized with virulent S. aureus following experimental aerosol exposure. Tracheas, livers, and hock joints of some market-age turkeys were naturally colonized with S. aureus and various species of coagulase-negative staphylococci.     

Equine hemostasis. Description, evaluation, and alteration

This is a review of equine hemostasis and is divided into three sections. The initial portion describes the normal hemostatic system and includes platelet function, coagulation, fibrinolysis and control processes. The second phase is devoted to laboratory tests of hemostasis, and the last section provides information on specific alterations.