The porcine immune system--differences compared to man and mouse and possible consequences for infections by Salmonella serovars

The porcine immune system differs in many aspects from that of humans and mice. Morphological differences in the lymphatic system (e.g. lymph nodes, Peyer's patches), and phenotypic differences in immune cells have been observed as well as functional differences in immune cell populations. Indeed, even the prenatal development of the embryonic piglet proceeds in a principally different way. However, it remains unclear to what extent these differences might contribute to the predisposition to and outcomes of bacterial infections, in particular those with zoonotic potential. In the following article we will review some of the peculiarities of the porcine immune system and consider possible implications for the course of infections in swine, with an emphasis on Salmonella serovars.     

Hyperthyroidism due to an intrathoracic tumour in a dog with test results suggesting hyperadrenocorticism

The elevated urinary corticoid/creatinine ratios of an 11-year-old Jack Russell terrier with polyuria were suppressible in a high-dose dexamethasone suppression test, which was suggestive of pituitary-dependent hyperadrenocorticism. The absence of physical and routine-laboratory changes compatible with hyperadrenocorticism and the relatively high plasma thyroxine concentration were the impetus for additional studies of thyroid and adrenocortical functions. A high plasma thyroxine concentration (62 nmol/l; 5.0 microg/100 ml) suggested the presence of hyperthyroidism. Radiography, (99m)TcO(4) (-) scintigraphy, ultrasonography, computed tomography and cytology revealed a hyperfunctioning intrathoracic thyroid tumour. In the low-dose dexamethasone suppression test, the plasma cortisol concentration exceeded the reference value of 40 nmol/l (1.4 microg/100 ml) at eight hours after dexamethasone administration (0.01 mg/kg intravenously), a test result compatible with hyperadrenocorticism. In conclusion, this report represents the first case of a dog with an autonomously hyperfunctioning thyroid tumour in the thorax. The elevated urinary corticoid excretion and the positive low-dose dexamethasone suppression test may be explained by alterations in cortisol metabolism, the stress of the hyperthyroid state or both.     

Effects of irrigation regimes on the yield and water use of strawberry

Summary Strawberry plants (Fragaria x annanasa D. cv Chandler) were grown in field plots and in drainage lysimeters under controlled soil moisture regimes. Four irrigation treatments were established by watering the plants when soil water potential reached -0.01, -0.03,-0.05 and -0.07 MPa. The maximum yield was attained at -0.01 MPa soil water potential. Differences in yield were caused by both changes in the number of fruits per plant and in the fresh weight per fruit. Yield reductions were associated with reductions in total assimilation rate resulting from the decreased assimilatory surface area in plants irrigated at lower soil water potentials. The crop water production function calculated on a fruit fresh weight basis resulted in a yield response factor (K _y) of 1.01.     

Comparison of antioxidant potency of commonly consumed polyphenol-rich beverages in the United States

A number of different beverage products claim to have antioxidant potency due to their perceived high content of polyphenols. Basic and applied research indicates that pomegranate juice (PJ), produced from the Wonderful variety of Punica granatum fruits, has strong antioxidant activity and related health benefits. Although consumers are familiar with the concept of free radicals and antioxidants, they are often misled by claims of superior antioxidant activity of different beverages, which are usually based only on testing of a limited spectrum of antioxidant activities. There is no available direct comparison of PJ's antioxidant activity to those of other widely available polyphenol-rich beverage products using a comprehensive variety of antioxidant tests. The present study applied (1) four tests of antioxidant potency [Trolox equivalent antioxidant capacity (TEAC), total oxygen radical absorbance capacity (ORAC), free radical scavenging capacity by 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP)]; (2) a test of antioxidant functionality, that is, inhibition of low-density lipoprotein (LDL) oxidation by peroxides and malondialdehyde methods; and (3) evaluation of the total polyphenol content [by gallic acid equivalents (GAEs)] of polyphenol-rich beverages in the marketplace. The beverages included several different brands as follows: apple juice (3), a?aí juice (3), black cherry juice (3), blueberry juice (3), cranberry juice (3), Concord grape juice (3), orange juice (3), red wines (3), iced tea beverages (10) [black tea (3), green tea (4), white tea (3)], and a major PJ available in the U.S. market. An overall antioxidant potency composite index was calculated by assigning each test equal weight. PJ had the greatest antioxidant potency composite index among the beverages tested and was at least 20% greater than any of the other beverages tested. Antioxidant potency, ability to inhibit LDL oxidation, and total polyphenol content were consistent in classifying the antioxidant capacity of the polyphenol-rich beverages in the following order: PJ>red wine>Concord grape juice>blueberry juice>black cherry juice, a?aí juice, cranberry juice>orange juice, iced tea beverages, apple juice. Although in vitro antioxidant potency does not prove in vivo biological activity, there is also consistent clinical evidence of antioxidant potency for the most potent beverages including both PJ and red wine.     

Assessing forest structure and function from spectral transmittance measurements: a case study in a Mediterranean holm oak forest

Annual changes in structural attributes and seasonal dynamics in water content, photosynthetic rate and light-use efficiency (LUE) were assessed by spectral transmittance for 4 years (1999-2003) in six stands of a Mediterranean holm oak forest. Green biomass, total biomass and leaf area index (LAI) were determined. In 1999, seasonal dynamics of net carbon dioxide (CO2) exchange and water content were measured. We recorded photosynthetically active radiation (PAR) transmittance and hyperspectral transmittance in the 400-1100 nm region and derived reflectance-based vegetation indices. Transmittance over the PAR region derived from either ceptometer or spectroradiometer measurements (PART and TPAR, respectively) was related to green and total biomass. Both PART and TPAR were also related to LAI (r=0.79 and r=0.70, respectively, P <0.001) and were appropriate for comparison among stands, whereas subtle changes in LAI within a stand were better assessed by the transmittance amplitude in the red edge region (TRE) (within a stand, r=0.77-0.99, P <0.001). Spectral transmittance-based indices successfully captured physiological processes that occurred on temporal (seasonal) and spatial scales. The transmittance-based water index (TWI) was related to both foliage and canopy water content (r=0.69, P <0.001). Estimates of foliage and canopy water content improved in dense (closed) stands (r=0.84 and r=0.87, respectively, P <0.001) compared with low-density stands. Under non-drought conditions, transmittance-based photochemical reflectance index (TPRI) was related to LUE (r=0.58, P <0.05) and net CO2 exchange (r=0.72, P <0.01), and the combined TPAR x TPRI index greatly improved these relationships (r=0.93 and r=0.84, respectively, P <0.01), indicating that both structural and physiological adjustments modified CO2 fixation capacity in these forest stands. Our novel approach to the study of transmitted radiation provides a tool for estimating structural and functional variables such as LAI, LUE and water content, which are key determinants of terrestrial productivity.     

Organic Food Demand: A Focus Group Study Involving Caucasian and African-American Shoppers

A focus group study using four groups of food shoppers provides insights into consumers’ knowledge, beliefs, and behaviors regarding organic foods. Two focus groups consisted of shoppers who regularly bought organic foods and two focus groups of shoppers who predominantly purchased conventional foods. Participants in one of the conventional groups were all Caucasian; in the other they were all African-American. While familiarity with organic foods was much lower in the African-American group, its members were more receptive and positive towards organic foods. Likewise, the African-American shoppers were more accepting of price premiums for organics foods. In comparing the two organic shopper groups with the two conventional shopper groups, it was found that the former were generally more knowledgeable about organic foods. They were also more likely to follow a special diet than conventional Caucasian shoppers. However, the behavior of organic shoppers varied widely. The research supports examining social justice and access as motivations for changing policies to support organic agriculture. Lydia Zepeda is a Professor of Consumer Science at University of Wisconsin and Senior Fellow of the Center for World Affairs and the Global Economy. Her research focuses on agricultural technology adoption, farm household decision making, and consumer perceptions and behavior towards agricultural technology and food. Hui-Shung Chang is a Senior Lecturer in the School of Economics at the University of New England, Armidale, New South Wales, Australia. Her research focuses on demand analysis and agribusiness marketing. Catherine Leviten-Reid is a research assistant and graduate student in the Department of Consumer Science at the University of Wisconsin–Madison. She is interested in household behavior and sustainable community development.     

Transition metal speciation in the cell: insights from the chemistry of metal ion receptors

The essential transition metal ions are avidly accumulated by cells, yet they have two faces: They are put to use as required cofactors, but they also can catalyze cytotoxic reactions. Several families of proteins are emerging that control the activity of intracellular metal ions and help confine them to vital roles. These include integral transmembrane transporters, metalloregulatory sensors, and diffusible cytoplasmic metallochaperone proteins that protect and guide metal ions to targets. It is becoming clear that many of these proteins use atypical coordination chemistry to accomplish their unique goals. The different coordination numbers, types of coordinating residues, and solvent accessibilities of these sites are providing insight into the inorganic chemistry of the cytoplasm.