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PubMed2004

Disinfectant decay and disinfection by-products formation model development: chlorination and ozonation by-products.

Comprehensive disinfectant decay and disinfection by-product formation (D/DBP) models in chlorination and ozonation were developed to apply to various types of raw and treated waters. Comparison of several types of models, such as empirical power function models and empirical kinetic models, was provided in order to choose more robust and accurate models for the D/DBP simulations. An empirical power function model based on dissolved organic carbon and other parameters (Empirically based models for predicting chlorination and ozonation by-products: haloacetic acids, chloral hydrate, and bromate, EPA Report CX 819579, 1998) showed a strong correlation between measured and predicted trihalomethane (THM) and haloacetic acid (HAA) formation for raw waters. Internal evaluation of kinetic-based models showed good predictions for chlorine decay and THM/HAA formation, but no significant improvements were observed compared to the empirical power function model simulations. In addition, several empirical models for predicting ozone decay and bromate (ozonation disinfection by-product) formation were also evaluated and/or developed. Several attempts to develop kinetic-based and alternative models were made: (i) a two-stage model (two separate decay models) was adapted to ozone decay and (ii) an ozone demand model was developed for bromate formation. Generally, internal evaluation of kinetic-based models for ozone decay showed significant improvements, but no significant improvements for the simulation of bromate formation were observed compared to the empirical power function model simulations. Additional efforts were performed to reduce the gaps between specific models and their actual application. For instance, temperature effects and configuration of ozone contactors were considered in actual application.

Acetic Acid↗
PubMed2000

Monitoring of fluorine in urine samples of patients involved in the tokyo sarin disaster, in connection with the detection of other decomposition products of sarin and the by-products generated during sarin synthesis.

We developed a new assay method for fluoride anion (F(-)) a specific metabolite of sarin. Trimethyifluorosilane (TMFS) was derivatized from F(-) with trimethylsilanol, and TMFS was detected with a GC-flame ionization detector (FID) and capillary column system. The linear range, detection limit and recovery rate were 0.02-10 ppm, 0. 01 ppm and 97.3-103.0%, respectively. The patients were reported to be exposed only once to the toxic substance (a bolus exposure). F(-) excretion in urine of the hospitalized patients demonstrated three or four peaks. Other common metabolites of sarin and by-products such as methylphosphonic acid (MPA) and isopropyl alcohol (IPA) also showed two or three peaks. These results suggested that the patients were exposed to not only sarin but also fluoride and isopropyl alcohol containing by-products. The sum of MPA excreted was 0.3-90 mM, far exceeding the human lethal dose of sarin. The residual acetyicholine esterase activity of erythrocytes on admission (4.7-57.2% of the individual reference value) of the patients showed statistically significant relationships only with the initial values of F(-) and the isopropyl methylphosphonate. This evidence also suggested the exposure to fluoride and isopropyl alcohol-containing by-products.

2-Propanol↗
PubMed1999

Glucose degradation product methylglyoxal enhances the production of vascular endothelial growth factor in peritoneal cells: role in the functional and morphological alterations of peritoneal membranes in peritoneal dialysis.

Peritoneal membrane permeability deteriorates in peritoneal dialysis (PD) patients. We test whether glucose degradation products (GDPs) in PD fluids, glyoxal, methylglyoxal and 3-deoxyglucosone, stimulate the production of vascular endothelial growth factor (VEGF), a factor known to enhance vascular permeability and angiogenesis. VEGF increased in cultured rat mesothelial and human endothelial cells exposed to methylglyoxal, but not to glyoxal or 3-deoxyglucosone. VEGF also increased in peritoneal tissue of rats given intraperitoneally methylglyoxal. VEGF and carboxymethyllysine (CML) (formed from GDPs) co-localized immunohistochemically in mesothelial layer and vascular walls of the peritoneal membrane of patients given chronic PD. By contrast, in the peritoneum of non-uremic subjects, VEGF was identified only in vascular walls, in the absence of CML. VEGF production induced by GDPs may play a role in the progressive deterioration of the peritoneal membrane.

Animals↗
PubMed2003

Sex and season influence gonadal steroid biosynthetic pathways, end-product production and steroid conjugation in blotched blue-tongued lizards (Tiliqua nigrolutea).

We examined differences in gonadal steroid production and biosynthetic pathway activity with changing reproductive condition and between sexes in the scincid lizard, Tiliqua nigrolutea. We observed clear seasonal and sexual variation in the production of androgens and steroid conjugates, but detected no 17beta-estradiol or 5alpha-dihydrotestosterone produced by the gonads. An alternative steroid, more polar than estradiol, was detected: an investigation of this steroid is reported separately [Gen. Comp. Endocrinol. 129 (2002) 114]. There were seasonal and sex-related differences in steroid biosynthetic pathway activity. The Delta5 pathway metabolite, dehydroepiandrosterone, was detected only in males, and only from incubations using regressed testicular tissue. There was also a seasonal difference between the sexes in rates of progesterone accumulation, although the absence of corresponding elevated plasma concentrations suggests that the role of progesterone switches from a directly acting hormone to a precursor for others during the reproductive cycle in females. These results suggest that within the traditional view that vertebrate biosynthetic pathway activity and end-products are phylogenetically conserved, there is likely to be considerably species- and/or genus-specific variation.

Animals↗
PubMed1997

Schwann cell extracellular matrix protein production is modulated by Mycobacterium leprae and macrophage secretory products.

Extracellular matrix (ECM) protein deposition is an important feature of leprous nerves, where Schwann cells (SCs) and macrophages are the main hosts for Mycobacterium leprae. Since, SCs are involved in the synthesis of ECM proteins and its production is regulated by macrophage secretory factors, the present study aimed to determine in vitro, the effect of M. leprae infection and macrophage secretory products on secretion of ECM proteins by SCs in two strains of mice, Swiss White (SW) and C57BL/6, that are known to differ in their nerve pathology and macrophage functions in response to infection. Following six days of M. leprae infection, SCs from SW mice responded with increased secretion of 14C-leucine radiolabelled proteins and a concomitant increase in laminin and collagens type I, III and IV, as determined by enzyme-linked immunosorbent assay. In contrast infected C57BL/6 SCs responded with decreased secretion of total proteins and fibronectin. Exposure of SCs to macrophage conditioned medium resulted in decreased ECM protein secretion in both strains of mice. This decrease was a function of protein breakdown by macrophage derived proteases and also active regulation by macrophage secreted cytokines. A similar effect of M. leprae and macrophage secretory products on SC metabolism in leprous nerves would have major ramifications on damage and repair activities. In addition ECM proteins would also influence the composition of the infiltrating cell population in lepromatous and tuberculoid nerves.

Animals↗
PubMed2002

Norethindrone acetate (NA) and ethinyl estradiol (EE) related oxidative transformation products in stability samples of formulated drug product: synthesis of authentic references.

Preparative chemical methods for the synthesis of eight oxidative transformation products of ethinyl estradiol (EE) and norethindrone acetate (NA) are described. The prepared materials are useful as reference materials and standards for pharmaceutical analysis of EE and NA as bulk chemical or in formulated product. All eight products result from oxidation of the A and/or B rings of the parent compounds. Oxidation of the heteroannular 3,5 dienyl acetate derivative of NA resulted in the 6 alpha-hydroxy, 6 beta-hydroxy and 6-keto NA. Oxidation of 6-keto NA led to the preparation of 6 alpha-hydroxy, 6 beta-hydroxy, 6-keto- and Delta(6) EE. Delta(11) EE was prepared from estrone.

Chromatography, High Pressure Liquid↗
PubMed1994

Manual semen collection from a Grevy's zebra stallion (Equus grevyi), onset of sperm production, semen characteristics, and cryopreservation of semen, with a comparison to the sperm production from a Grant's Zebra stallion (Equus burchelli boehmi).

A manual technique was used to collect representative ejaculates from an unrestrained Grevy's zebra stallion beginning at 13 mo of age to determine the onset of sperm production, to calculate the number of spermatozoa produced per ejaculate, and to determine any seasonality associated with sperm production. Spermatozoa first appeared in the ejaculate at 31 mo of age. By 48 mo of age the zebra was producing up to 40 billion spermatozoa per ejaculate. Progressive sperm motility ranged from 75 to 95%. Gel-free semen volume averaged 75 to 120 ml/ejaculate. Gel volume ranged from 0 to 1100 ml/ejaculate. Semen was frozen in 2 different extenders in 0.5-ml PVC straws. The post-thaw motility of cryopreserved spermatozoa ranged from 30 to 70%. A domestic horse mare became pregnant on the first cycle after insemination with frozen-thawed spermatozoa from this zebra. Sperm production data obtained from semen collections made on a Grant's Zebra stallion from 3 to 8 yr of age is presented for comparison of the 2 species.

Journal Article↗
PubMed1999

In vitro embryo production in the cow: an effective alternative to the conventional embryo production approach.

Development of new technology related to in vitro embryo production has allowed for the commercial use of this method of reproduction. In the present work, we evaluate the efficiency of this technology compared with conventional embryo production based on results obtained with a standard procedure, including the sexing of embryos. The donor animals were mature nonlactating dairy cows (n = 92) kept under a constant environment and feeding program in an ET center. Ultrasound guided transvaginal ovum pick-up following 48 h pre-treatment with FSH has been used for the IVF-IVC protocol. A total of 437 oocyte recovery sessions performed on 92 cows yielded 4145 oocytes, which were used in an IVF-IVC protocol. Using the conventional approach, 156 embryo collections on 49 cows yielded 1652 ova and embryos. All Quality 1 and 2 embryos were sexed by a PCR procedure, and embryos of the desired sex were transferred to synchronized recipients located at the center. The results obtained in the IVF protocol showed that 4 oocyte collections per cow performed within 60 d, yielded 38 oocytes, which resulted in 18.8 viable embryos, of which 7.05 were female. After transfer of the female embryos, an average of 3.8 recipients were pregnant at 60 d. One embryo collection under the conventional approach yielded an average of 1.2 female pregnancies, which was confirmed during the same 60-d time period. These results indicate that IVF procedures can effectively replace conventional embryo production methods when a predetermined number of pregnancies of known sex are needed within a short period of time.

Animals↗
PubMed1997

Products from mast cells influence T lymphocyte proliferation and cytokine production--relevant to allergic asthma?

In IgE allergic diseases both mast cells and T lymphocytes play an important role. Whereas mast cels have been implicated in immediate allergic responses, T lymphocytes mediate subsequent late phase responses and chronic inflammation. Here we review possible links between the early mast cell activation and the later T lymphocyte stimulation. Products from mast cells were found to exert effects on T lymphocytes. Human Mast Cell line-1 (HMC-1) mast cells modulated proliferation and cytokine production of a human CD8+ T-cell clone in vitro. Activated mast cells seemed to drive this CD8+ T-cell clone towards a more pronounced T (helper) 1 type of response, simultaneously decreasing T-cell numbers. It is hypothesized that this might be a negative feed back mechanism operating in allergic subjects, by which the Th2-driven IgE production and eosinophilia are counteracted.

Animals↗
PubMed1999

Occurrence of nisin Z production in Lactococcus lactis BFE 1500 isolated from wara, a traditional Nigerian cheese product.

Screening for bacteriocin production of 500 strains of lactic acid bacteria (LAB) from various African fermented foods resulted in the detection of a bacteriocin producing Lactococcus lactis (BFE 1500) isolated from a dairy product called wara. The bacteriocin inhibited not only the closely related LAB, but also strains of Listeria monocytogenes, Listeria innocua, Clostridium butyricum, Clostridium perfringens, Bacillis cereus and Staphylococcus aureus. It was heat stable even at autoclaving temperature (121 degrees C for 15 min) and was active over a wide pH range (2-10), but highest activity was observed in the lower pH range. The bacteriocin was inactivated by alpha-chymotrypsin and proteinase K, but not by other proteases. Growth kinetic assay indicated stronger growth inhibition by the bacteriocin produced by Lc. lactis BFE 1500 on L. monocytogenes WS 2250 and B. cereus DSM 2301 than with the nisin A producing strain DSM 20729. Polymerase chain reaction indicated the presence of the nisin operon in strain BFE 1500 and sequencing of its structural gene showed that Lc. lactis BFE 1500 produced the natural nisin variant, nisin Z, as indicated by the substitution of asparagine residue instead of histidine at position 27. The genetic determinants for bacteriocin production in strain BFE 1500 are located on a conjugative transposon. The ability of the bacteriocin produced by Lc. lactis BFE 1500 to inhibit a wide range of food-borne pathogens is of special interest for food safety, especially in the African environment with perennial problems of poor food hygiene.

Amino Acid Sequence↗
PubMed1991

Nitrite production by activated murine macrophages correlates with their toxoplasmastatic activity, Ia antigen expression, and production of H2O2.

Activated macrophages have various characteristics in common with exudate and resident macrophages, but the ability to inhibit intracellular proliferation of the protozoa Toxoplasma gondii, the expression of Ia antigen and the capacity to produce H2O2 varies among these cells. Assessment of these features of macrophages, which are generally used as criteria for macrophage activation, has certain drawbacks. Since activated murine macrophages, but not exudate or resident macrophages, produce considerable amounts of NO2-, assessment of NO2- production by these cells might serve as a measure of macrophage activation. The aim of the present study was to find out whether NO2- production by murine peritoneal macrophages correlates with the three generally accepted criteria for macrophage activation. Quantitative data on resident, exudate and activated macrophages revealed that the production of NO2- stimulated by a calcium-ionophore correlates best with the ability to inhibit the proliferation of T. gondii, Ia antigen expression, and capacity to produce H2O2. Because it is rapid and easy to perform, measurement of the amount of NO2- produced by murine macrophages stimulated with a calcium-ionophore offers the most practical criterion for distinction between activated macrophages and exudate and resident macrophages.

Animals↗
PubMed1998

Biological response modifiers: interferons, interleukins, recombinant products, liposomal products.

The concept of enhancing the normal immune response against infections and neoplasms has been considered for decades. The administration of various natural and synthetic products to simulate systemic infections has largely given over to the idea that specific cytokines can be used effectively when administered systemically. Interferons, interleukins, and hematopoietic growth factors may offer substantial clinical benefit in chronic viral infections, and cancers such as osteosarcoma, melanoma, and lymphosarcoma. Erythropoietin has been shown to have great utility in the management of chronic renal failure. At this point in time, only recombinant products derived from humans are commercially available, and they are expensive and not licensed for use in companion animals. Nevertheless, these products may have significant clinical impact on several highly fatal disorders of dogs and cats. When administered systemically, cytokines perturb complex regulatory pathways, and serious side effects may occur. Innovative delivery methods, such as liposomes, gene therapy, and even oral administration may increase the therapeutic index of these molecules. Biological response modification, cytokine biology, and associated delivery systems are rapidly changing fields, and the small animal veterinarian will need to watch for significant advances in these areas over the next several years.

Animals↗
PubMedDate not supplied

Production of nitric oxide (NO) in human hydatidosis: relationship between nitrite production and interferon-gamma levels.

Human hydatidosis is characterized by a prolonged coexistence of parasite (Echinococcus granulosus) and host without effective rejection. The basis of the immune response of the patient is poorly understood. Previously, we reported the presence of IFN, TNF-alpha and IL-6 activities in the serum of patients with liver and lung hydatidosis. In the present work, we have investigated the production of nitrite (NO2-) in the serum of hydatidic patients carrying hepatic and pulmonary cysts (range 36-300 microM). Our present data show a correlation between the production of nitrite + nitrate (NO2- + NO3-) and that of circulating cytokines IFN and IL-6. In relapsing patients who did not produce IFN and IL-6, the observed serum NO2- concentrations were low (range 10-37.2 microM), as compared to those detected in patients before surgery. Induction of NO synthase in leukocytes from hydatidic patients was induced by stimulating these cells with a specific parasitic antigen, Antigen-5, as assessed by the increased levels of NO3- + NO2- in the range of 60-85 microM for patients with liver hydatidosis, as compared to the 20-25 microM detected in healthy controls. Collectively, our data indicate that NO2- + NO3- levels correlate with IFN levels and immunoreactivity, and overall suggest that IFN-gamma and nitric oxide production together play a role in the host defense mechanisms in human hydatidosis.

Adult↗
PubMed1999

Effect of Fasciola gigantica somatic extracts and excretory/secretory products on superoxide production by activated neutrophils.

Somatic extracts and excretory/secretory (ES) products from Fasciola gigantica suppress the release of toxic oxygen intermediates by activated sheep neutrophils. At the concentrations used both the somatic extracts and ES products had no effect on neutrophil viability and in both cases the inhibitory effect was reversible. In the somatic extracts, heating or treatment with trypsin destroyed the inhibitory effect. However, the ES products contained at least two immunomodulatory factors. One was less than 10 kDa, the other greater than 50 kDa and both factors were heat and trypsin stable. By acting locally and only causing temporary inhibition of neutrophil function F. gigantica can protect itself from immune mediated oxidative damage without compromising the host's response elsewhere.

Animals↗
PubMed1978

Utilization of industrial and agricultural by-products for fungal amylase production.

Attempts were made for using industrial and agricultural by-products and wastes as carbon and nitrogen sources in fermentation medium for alpha-amylase production by Aspergillus niger NRRL-337. The original carbon source of the basal medium was replaced by one of the following materials: rice bran, wheat bran, corn bran, corn starch, cane molasses, and glucose syrup. Rice bran proved to be the best carbon source that secured the highest amylase activity. The nitrogen source of the basal medium was then replaced by different cheap materials, viz: dried yeast, corn steep liquor, gluten-30, gluten-50, and corn steep precipitate. Corn steep precipitate proved to be superior in amylase production. In consideration of these results an economical medium that secured high activity, containing the following ingredients, was suggested: 2.5% corn steep precipitate, 7.2% rice bran, 0.1% MgSO4, 0.1% KH2PO4, and 0.1% CaCO3. From this medium fungal amylase was precipitated and purified. The pure enzyme gave the highest activity at 40 degrees C and pH 4.3.

Amylases↗
PubMed1991

Grazing management as it affects nutrition, animal production and economics of beef production.

Until recently, the nutritional fate of the grazing animal has been largely ignored by both animal and range scientists despite the economic dependence of the extensive livestock industry on nutrition from grass. Of the three factors that can be manipulated to improve profit gross margin per animal, is one that is directly affected by nutrition and, hence, grazing management. The relationship between economics and grazing management may be summarized as: Gross margin = f(Animal Performance); Animal Performance = f(nutrition); Nutrition = f(grazing). Economical beef production must consider the needs of the animal and the forage plant at the same time. The health of the sward must be maintained while improving individual animal performance and simultaneously increasing stocking rate. Generally, plants that have been defoliated require a period of recovery before again being grazed. A sward is kept in a vigorous state by preventing repetitive defoliation at the one extreme, and avoiding excessive shading (mature growth) of photosynthetic material at the other. This state is best achieved where livestock grazing is controlled. For any individual paddock, periods of grazing are followed by periods that allow adequate physiologic recovery of the plants. A grazing regimen that keeps the plant in a healthy state is fortuitously also well suited to the nutritional requirements of the animal. Animals on overgrazed pastures are likely to suffer from inadequate feed intake because of deficiencies in feed quantity. Conversely, on over-rested pastures, intake deficiency results from paucity in feed quality. On most unmanaged ranges, overgrazed and over-rested plants are likely to be found side by side. By controlling duration of the rest period as well as duration of the grazing period through pasture subdivision, requirements of both the plant and the animal can be met. With artificially high economic demands placed on animal production, some form of supplementation is required in most modern livestock situations. Whereas energy is frequently the nutrient limiting production it is seldom economically feasible to supplement the grazing animal directly with energy. Protein supplementation to increase forage intake, and thus indirectly energy intake, has become standard practice in many grazing situations. When there is adequate forage with a low crude protein content (less than or equal to 7%), microbially degradable protein is the preferred choice. However, when the animals are in an energy deficient state, either through a shortage of available forage or because their requirements exceed energy intake levels, by-pass protein is required.

Animal Feed↗
PubMedDate not supplied

Spontaneous shift of an HSV type 1 productive, persistently infected macrophage-like culture to a non-productive culture.

A herpes simplex virus type 1 (HSV1) productive, persistently infected murine macrophage-like culture was obtained by infection at low multiplicity (0.001). Persistent cultures were characterized by spontaneously ceasing to produce infectious viruses after initial HSV1 production. A similar pattern of virus production was observed in cultures obtained by reinfection of the persistent macrophages with the original virus. Nonetheless, in persistent and reinfected cultures (17/18) which did not produce infectious viruses, viral proteins were detected by immunoblot, although their molecular weight, number and pattern differed among the cultures.

Animals↗
PubMed2003

Expression of a novel regenerating gene product, Reg IV, by high density fermentation in Pichia pastoris: production, purification, and characterization.

Human regenerating (Reg) gene products are regionally expressed by gut-derived tissues, and are markedly up-regulated in cancer and in diseases characterized by mucosal injury. We recently identified Reg IV, a novel regenerating gene product that is uniquely expressed by the normal distal gastrointestinal mucosa. The function remains poorly understood due to the lack of significant purified Reg IV for biochemical and functional studies. Recombinant human Reg IV was efficiently expressed under the control of the AOX1 gene promoter in Pichia pastoris using the MutS strain KM71H. We describe the unique conditions that are required for efficient production of Reg IV protein in high density fermentation. Optimal protein expression was obtained by reduction of the fermentation temperature and addition of casamino acids as a supplemental nitrogen source and to minimize the activity of yeast produced proteases. Recombinant Reg IV protein was purified by tangential flow filtration and reverse phase chromatography. The purified protein was characterized by amino terminus sequence analysis and MALDI-TOFMS showing that the engineered protein had the expected sequence and molecular weight without secondary modification. Recombinant Reg IV was further characterized by specific monoclonal and polyclonal reagents that function for Western blot analysis and for immunolocalization studies.

Amino Acid Sequence↗