In vivo erythrocyte sickling in the Japanese sika deer (Cervus nippon): methodology.

The Japanese sika deep (Cervus nippon) proved to be a suitable animal model for the study of acute phases of in vivo erythrocyte sickling. Ophthalmologic studies can be conducted during or after 1 to 6 hours of effective in vivo sickling. Intravenous administration of 1.75 to 3.5% sodium bicarbonate solution at a rate of 500 to 1,000 ml per hour produced a transient state of alkalosis and in vivo erythrocyte sickling in the sika deer. The percentage of sickled erythrocytes increased as the blood pH increased. Concurrently, the packed cell volume decreased. Sickling was enhanced by 100% oxygen ventilation after endotracheal intubation and light anesthetization. After the induction of erythrocyte sickling, a sickling-reversal phenomenon occurred despite continued bicarbonate administration. During the course of this reversal, the percentage of sickled erythrocytes steadily decreased, the venous blood pH decreased, and the packed cell volume slowly increased. Because of the sickling-reversal phenomenon, chronic erythrocyte sickling was not achieved.     

Phorbol ester action is independent of viral and cellular src kinase levels

Treatment of normal chick embryo fibroblasts with phorbol myristate acetate causes those cells to express many of the phenotypic properties of virally transformed cells and also enhances the expression of transformed properties in Rous sarcoma virus-transformed chick embryo fibroblasts. We report here that phorbol myristate acetate has little or no effect on the level of protein kinases encoded by the viral src or endogenous sarc genes.     

Validity and reliability of a calcium checklist in early elementary-school children

OBJECTIVE: To create, validate and assess the reliability of a checklist to measure calcium intake in children. DESIGN: Calcium intakes from a checklist and parent-assisted 24-h dietary recall were compared. Checklist reliability was assessed separately. SETTING: After-school programmes in the United States. SUBJECTS: Forty-two children (18 males, 24 females, age = 8.0 +/- 0.9 years) participated in the validation analysis and 49 children (28 males, 21 females, age = 7.5 +/- 0.9 years) in the reliability analysis. RESULTS: No differences in mean calcium intakes were found by method or gender. The checklist correlated well with recall among girls (r = 0.65, P = 0.01) but not boys (r = -0.33, P = 0.19). Agreement over time was above 80% for most foods. CONCLUSION: The calcium checklist is useful for assessing calcium intake among groups of 6-10-year-old children in settings that preclude parental assistance. More research is needed to improve accuracy among boys.     

Spatial configuration becomes more important with increasing habitat loss: a simulation study of environmentally-transmitted parasites

Context

Landscape changes can be an important modifier of disease. Habitat fragmentation commonly results in reduced connectivity in host populations and increased use of the remaining habitat. For environmentally transmitted parasites, this presents a possible trade-off between transmission potential at the local and global level.

Objectives

We quantify the effects of fragmentation on the transmission of an environmentally transmitted parasite, teasing apart the relative effects of habitat composition and configuration on both host movement behaviour and subsequent infection patterns.

Methods

We use a spatially-explicit epidemiological model to simulate the effects of habitat fragmentation, using, as an example, whipworm (Trichuris sp.) within a red colobus monkey population (Procolobus rufomitratus).

Results

We found that habitat fragmentation did not always lead to a trade-off between population connectivity and concentration of habitat use in host movement behaviour or in final population infection patterns. However, our simulation results suggest the spatial configuration of the remaining habitat became increasingly influential on behavioural and infection outcomes as habitat was removed. Additionally, we found common fragmentation metrics provided little ability to explain variation in propagation of infections.

Conclusions

Our results suggest an interaction between habitat configuration and composition should be considered when assessing disease related impacts of habitat fragmentation on environmentally transmitted parasites, especially in cases where habitat loss is high (≥?30%). We also propose that spatially-explicit simulations that capture a host’s response to fragmentation could aid in the development of novel landscape metrics targeted towards specific host-parasite-landscape systems.

     

Analysis of environment-recruitment associations for a coastal red drum population reveals consistent link between year class strength and early shifts in nearshore winds

The identification of factors contributing to strong year classes of marine fishes has been a constant goal toward a mechanistic understanding of recruitment variability. Here, we explored a 26-year time series of the abundance of early juvenile red drum along the North Carolina coast to identify environmental features associated with variable recruitment success. The study location was near the northern edge of the species latitudinal range, and we hypothesized that consistent environmental forcing would be linked to the formation of strong red drum year classes. Patterns of variability in seasonal environmental features were disaggregated into multiple forms of temporal periodicity and analyzed using generalized additive models. We also contrasted patterns of environmental variation that occurred during the strongest recruitment events with those coinciding with the weakest red drum year classes. The early shift, during August, to favorable wind conditions was the most consistent environmental feature associated with red drum recruitment success. The combined duration and magnitude of N and NE winds during August of strong recruitment years was nearly double the level observed during weak recruitment years. Elevated nearshore sea surface temperatures early in the spawning season were also found to occur during years that produced strong year classes. Coastal productivity, indexed using chlorophyll a concentration, was positively associated with red drum recruitment, but also highlighted the need for more spatially resolved productivity data. Our findings highlight the importance of environment-recruitment linkages for marine fishes, especially near distributional boundaries where conditions to promote year class success can be brief.     

Method for the gas chromatographic assay with mass selective detection of trichloro compounds in corks and wines applied to elucidate the potential cause of cork taint

To investigate the role of trichloro compounds as a potential cause of "cork taint" in wine, an assay for trichloroanisole (TCA) and trichlorophenol (TCP) in corks and wine was developed utilizing solid phase extraction on a C(18) cartridge followed by gas chromatography with mass selective detection. Recovery and imprecision for TCA were 86-102 and 1.6-5.8%, respectively, and for TCP 82-103% and 1.7-3.9%, respectively. Limits of detection and quantitation were 0.1 and 2 ng/L, respectively, for TCA, and 0.7 and 4 ng/L, respectively for TCP. A survey of 2400 commercial wines revealed a higher incidence of cork taint in white wine than in red and in wines utilizing composite cork closures; wines from central Europe and Spain had higher overall rates of contamination and those from Canada and Italy the lowest. Significant but modest associations were found between the TCA and TCP contents of the wines and corks, but many wines exhibiting cork taint had low or undetectable concentrations of TCA. Over a 12-month period, experimentally bottled wines exhibited a slow increase in TCA and TCP content while cork closures manifested a decrease; most bottles showing cork taint contained low levels of TCA, and TCP concentrations were well below the sensory threshold. Neither compound was cytotoxic to human cell lines in culture up to final concentrations of 500 ng/mL. It was concluded that these two trichloro compounds are, at most, minor components of cork taint in commercial wines.     

Vesicular and synaptoplasmic synthesis of acetylcholine

The synthesis and distribution of acetylcholine has been studied in the isolated synaptosome. Binding or contamination of [(14)C]acetylcholine in the synaptic vesicle fraction represents 1.5 percent of the total amount found in the synaptoplasm (synaptosomal cytoplasm). However, when the [(14)C]acetylcholine is derived solely by synthesis from labeled choline, then the labeled acetylcholine in the synaptic vesicle is 15 percent of the amount of acetylcholine synthesized in the synaptoplasm. The results suggest that the [(14)C]acetylcholine found in the vesicle fraction of synaptosomes incubated with labeled choline is due to vesicular synthesis.     

Amacrine-signaled loss of intrinsic axon growth ability by retinal ganglion cells

The central nervous system (CNS) loses the ability to regenerate early during development, but it is not known why. The retina has long served as a simple model system for study of CNS regeneration. Here we show that amacrine cells signal neonatal rat retinal ganglion cells (RGCs) to undergo a profound and apparently irreversible loss of intrinsic axon growth ability. Concurrently, retinal maturation triggers RGCs to greatly increase their dendritic growth ability. These results suggest that adult CNS neurons fail to regenerate not only because of CNS glial inhibition but also because of a loss of intrinsic axon growth ability.     

Potentiation of 5-Fluorouracil Inhibition of Flexner-Jobling Carcinoma by Glucose

A significant potentiation of the antitumor action of 5-fluorouracil in rats bearing the Flexner-Jobling carcinoma is produced by the intraperitoneal administration of large doses of glucose.     

Morphine: conditioned increases in self-administration in rhesus monkeys

Operant responding in three monkeys was maintained by intravenous presentations of morphine. Nalorphine produced reliable increases in morphine-reinforced responding. With successive daily nalorphine injections there was a decreased latency of self-administration responding for morphine, and substituted saline injections produced conditioned increases in morphine-reinforced responding.