Effect of dietary zinc levels on health and productivity of gilts and sows through two parities

The influence of 0, 50, 500 or 5,000 ppm supplemental Zn on productive characteristics, weight change, and serum and organ mineral concentrations of 60 crossbred and purebred Yorkshire gilts was evaluated. Gilts were fed their respective treatment from 30 kg body weight until the completion of two parities. Sows fed 5,000 ppm supplemental Zn weighed significantly less than sows from the other treatments when killed. Serum alkaline phosphatase activity was higher for the sows fed the highest level of Zn in all replications at 10 and 14 mo of age than for sows from the other treatments. Sows fed 0, 50 or 500 ppm had lower serum Zn and higher serum Cu concentrations than sows fed 5,000 ppm Zn at 10 and 14 mo of age. The number of pigs farrowed (total and live) and birth weight were not affected by dam's dietary treatment. However, sows receiving no additional Zn had a higher number of abnormal pigs/litter than sows on the other treatments. Sows fed 5,000 ppm additional Zn weaned fewer pigs that weighed less at weaning than sows on the other treatments. The concentration of Zn in the sow's liver increased significantly and liver Cu decreased as dietary level of Zn increased. Sows receiving 5,000 ppm Zn had lower hepatic Fe stores compared with sows receiving 500 ppm Zn. Elevated renal Cu and Zn concentrations were found in sows fed the highest level of Zn supplementation. The Zn concentration was higher and the Cu concentration lower in the aorta of sows fed 5,000 ppm Zn compared with sows fed 0 or 50 ppm additional Zn. Incidence of osteochondrosis was higher in sows supplemented with 5,000 ppm Zn than for sows from the other treatments.     

Characterization of benzodiazepine receptors in primary cultures of fetal mouse brain and spinal cord neurons

Primary cultures of fetal mouse brain and spinal cord were examined for the presence of binding sites for [3H]diazepam. Both brain and spinal cord cultures contain high affinity binding sites which resemble benzodiazepine receptors found in mammalian CNS with respect to both pharmacologic profile and response to exogenously applied GABA. These observations, coupled with the electrophysiologic properties of these cells suggest that primary cultures of fetal mouse brain and spinal cord may be valid models for studying the role and regulation of the benzodiazepine receptor.     

Monitoring biodegradation of methyl tert-butyl ether (MTBE) using compound-specific carbon isotope analysis

Methyl tert-butyl ether (MTBE), the most common gasoline oxygenate, is frequently detected in surface water and groundwater. The aim of this study was to evaluate the potential of compound-specific isotope analysis to assess in situ biodegradation of MTBE in groundwater. For that purpose, the effect of relevant physical and biological processes on carbon isotope ratios of MTBE was evaluated in laboratory studies. Carbon isotope fractionation during organic phase/gas-phase partitioning (0.50 +/- 0.15@1000), aqueous phase/gas-phase partitioning (0.17 +/- 0.05@1000), and organic phase/aqueous-phase partitioning (0.18 +/- 0.24@1000) was small in comparison to carbon isotope fractionation measured during biodegradation of MTBE in microcosms based on aquifer sediments of the Borden site. In experiments with MTBE as the only substrate and a cometabolic experiment with 3-methypentane as primary substrate, MTBE became enriched in 13C by 5.1 to 6.9@1000 after 95 to 97% degradation. For both experiments, similar isotopic enrichment factors were obtained (-1.52 +/- 0.06 to -1.97 +/- 0.05@1000). Biodegradation of TBA, which accumulated transiently in the cometabolic microcosms, was also accompanied by carbon isotope fractionation, with an isotopic enrichment factor of -4.21 +/- 0.07@1000. This study suggests that carbon isotope analysis is a potential tool to trace in situ biodegradation of MTBE and TBA and thus to better understand the fate of these contaminants in the environment.     

Antecedents of stressful experiences: Depressive symptoms, self-esteem, gender, and coping.

Numerous studies have identified depressive symptoms as antecedent to stressful experiences. However, the interrelations of depressive symptoms, personal resources, and coping as antecedents of stressful experiences are largely unknown. For this investigation, a prospective design was used to test a model estimating two categories of daily hassles at Time 2 in relation to depressive symptoms, self-esteem, gender, coping, and daily hassles at Time 1. Utilizing simultaneous equations, direct effects were observed for depressive symptoms, Time 1 hassles, gender, and avoidance coping in relation to category of hassles at Time 2. Depressive symptoms and avoidance coping were observed to be mediators for gender and self-esteem. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Subconjunctival mitomycin C for the treatment of ocular cicatricial pemphigoid

PURPOSE: The authors performed a prospective evaluation of the efficacy of treating ocular cicatricial pemphigoid (OCP) with subconjunctival mitomycin C. DESIGN: Unmasked, prospective, internally controlled case series. METHODS: Patients were eligible for treatment with subconjunctival mitomycin C under three criteria: (1) significant complications of systemic immunosuppressant therapy; (2) markedly asymmetric conjunctival disease; and (3) end-stage OCP. All patients received monocular subconjunctival injections of 0.25 ml of 0.2 mg/ml mitomycin C to both the superior and inferior bulbar conjunctivae in the eye with the more severe disease. RESULTS: Nine eyes of nine patients (mean age, 74 years) were treated with subconjunctival mitomycin C to the more-involved eye and were followed for a mean of 23.5 months (range, 12-40 months). Eight of nine patients showed quiescence of their OCP in the treated eye based on serial evaluation of conjunctival cicatrization and grading of conjunctival erythema. Five of the nine untreated eyes showed progression of the conjunctival disease. One patient required concomitant systemic immunosuppressive therapy after subconjunctival mitomycin C. Two patients underwent successful visual rehabilitative surgery in the mitomycin C-treated eye. CONCLUSION: The use of subconjunctival mitomycin C may be effective in preventing progression of conjunctival cicatrization and erythema in patients with OCP. No complications of mitomycin C treatment were noted. Long-term follow-up and further investigation into the efficacy of subconjunctival mitomycin C in the management of OCP is warranted.     

On metaphor in psychology and physics: Reply to Farrell.

Replies to the comments of E. Farrell (see record 1986-26104-001) on the analysis by the present authors (see record 1986-10704-001) of applications of metaphor in the history of physics and psychology. It is suggested that although metaphor is an element in the complex that makes up a research tradition, its status is no higher than that of any of the other elements, any of which may influence the metaphor or be influenced by it. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distribution and Accumulation of the Mycotoxin Lolitrem B in Neotyphodium lolii- Infected Perennial Ryegrass

The symbiotic relationship between perennial ryegrass and its endophytic fungus, Neotyphodium lolii, is of considerable agronomic significance in New Zealand. Livestock ingesting N. lolii-infected perennial ryegrass may succumb to a neuromuscular condition, ryegrass staggers, the probable cause of which has been identified as the endophyte-produced indole–diterpenoid mycotoxin lolitrem B. The effects of plant component, plant reproductive development, and plant management (clipping) on the concentration and accumulation of lolitrem B were investigated. Eight different naturally occurring perennial ryegrass–N. lolii associations were cloned. They were either trimmed regularly to maintain their vegetative state (V clones) or not trimmed at all to enable full plant reproductive development (R clones). At times that corresponded approximately with the start, middle, and end of the plant reproductive phase, V and R clones of each grass–endophyte association were destructively harvested. After dissection into a number of plant components, harvested material was analyzed for lolitrem B content by HPLC. Analyses were also performed on all clippings taken from the V clones. Highest lolitrem B concentrations in vegetative parts were found in older leaf sheaths and dead leaves. Towards the end of the plant reprodutive phase, dead leaves also contained a large proportion of the total lolitrem B content of the V clones. The highest concentration of lolitrem B was found in the seed, which accounted for nearly 60% of the total quantity in R clones. Leaf blades, young leaf sheaths, roots, and crowns generally contained low to moderate concentrations. In late spring, mean concentrations in R and V clones were similar. By the time mature seed was present (mid-summer), mean concentrations in R clones were three times higher than in V clones. This difference was attributed largely to the contribution by the seed in the R clones. The implications of these findings in relation to ryegrass staggers in livestock are discussed.