Association between IgM Anti-Herpes Simplex Virus and Plasma Amyloid-Beta Levels

OBJECTIVE: Herpes simplex virus (HSV) reactivation has been identified as a possible risk factor for Alzheimer's disease (AD) and plasma amyloid-beta (Aβ) levels might be considered as possible biomarkers of the risk of AD. The aim of our study was to investigate the association between anti-HSV antibodies and plasma Aβ levels. METHODS: The study sample consisted of 1222 subjects (73.9 y in mean) from the Three-City cohort. IgM and IgG anti-HSV antibodies were quantified using an ELISA kit, and plasma levels of Aβ(1-40) and Aβ(1-42) were measured using an xMAP-based assay technology. Cross-sectional analyses of the associations between anti-HSV antibodies and plasma Aβ levels were performed by multi-linear regression. RESULTS: After adjustment for study center, age, sex, education, and apolipoprotein E-e4 polymorphism, plasma Aβ(1-42) and Aβ(1-40) levels were specifically inversely associated with anti-HSV IgM levels (β = -20.7, P=0.001 and β = -92.4, P=0.007, respectively). In a sub-sample with information on CLU- and CR1-linked SNPs genotyping (n=754), additional adjustment for CR1 or CLU markers did not modify these associations (adjustment for CR1 rs6656401, β = -25.6, P=0.002 for Aβ(1-42) and β = -132.7, P=0.002 for Aβ(1-40;) adjustment for CLU rs2279590, β = -25.6, P=0.002 for Aβ(1-42) and β = -134.8, P=0.002 for Aβ(1-40)). No association between the plasma Aβ(1-42)-to-Aβ(1-40) ratio and anti-HSV IgM or IgG were evidenced. CONCLUSION: High anti-HSV IgM levels, markers of HSV reactivation, are associated with lower plasma Aβ(1-40) and Aβ(1-42) levels, which suggest a possible involvement of the virus in the alterations of the APP processing and potentially in the pathogenesis of AD in human

Salt Tolerance in the Halophyte Suaeda maritima L.Dum.: Abscisic Acid Concentrations in Response to Constant and Altered Salinity

Endogenous abscisic acid contents were measured by gas-liquid chromatography in shoots of Suaeda maritima growing both in the steady state over a range of salinities and over a time-course following an increase in the culture solution salinity of between approximately 100 and 400 mol m−3 NaCl. In steady-state plants, the ABA content was maximal in the absence of salt at 41 ng g−1 fr. wt., declining to a minimum at 200 mol m−3 NaCl of 24 ng g−1 fr. wt. Increase of culture solution salinity resulted in a marked increase in shoot ABA which was maximal after 6 h or 24 h in plants previously growing at 200 mol m−3 NaCl and in the absence of salt, respectively. Additionally, culture solution water potentials were lowered by 1.0 MPa (equivalent to raising the salt concentration by around 200 mol m−3); this resulted in a similar increase in endogenous ABA content to that brought about by an iso-osmotic salt increase. Results are discussed in relation to the possible role of ABA in halophyte salt tolerance mechanisms

Corrigendum

The units for the respiration rates on page 207, lines 26 and 27, Table I should be '~l (g ethanol insoluble dry weight)-' min-" and not 'pl (g ethanol insoluble dry weight )-i h-"

Some effects of sodiumchloride on cells of ricecultured in vitro

Rice (Oryza sativa L.) varieties differ in the salt resistance of their cells in vivo; that is, different degrees of cellular damage are associated with similar concentrations of NaCl in the leaf tissue in different rice varieties (Yeo and Flowers, Physiol. Plant., 59 (1983) 189). Cells of two varieties differing in this respect were cultured in a liquid medium and the rate of oxygen uptake of cells which had been grown for up to 5 weeks in NaCl and in concentrations as high as 600 mol m−3 measured by conventional manometry. Sodiumchloride at up to 200 mol m−3 had little effect on oxygen uptake by either variety although cells of one variety were eventually killed by 600 mol m−3 NaCl. The results are discussed in relation to the value of tissue-culture in screening plants for resistance to salinity and to the effects of salinity on cells in the intact plant

The Use of 14C-Ethane Diol as a Quantitative Tracer for the Transpirational Volume Flow of Water and an Investigation of the Effects of Salinity upon Transpiration, Net Sodium Accumulation and Endogenous ABA in Individual Leaves of Oryza sativa L.

Oryza sativa L. (rice) seedlings growing in saline conditions exhibit pronounced gradients in leaf sodium concentration which is always higher in the older leaves than the younger ones. Individual leaf transpiration rates have been investigated to discover whether movement of sodium in the transpiration stream is able to explain these profiles from leaf to leaf. The use of 14C labelled ethane diol to estimate transpiration was evaluated by direct comparison with values obtained by gas exchange measurements. Ethane diol uptake was linearly related to the transpirational volume flow and accurately predicted leaf to leaf gradients in transpiration rate in saline and non-saline conditions. 14C-ethane diol and 22NaCl were used to compare the fluxes of water and sodium into different leaves. The youngest leaf showed the highest transpiration rate but the lowest Na accumulation in saline conditions; conversely, the older leaves showed the lower transpiration rates but the greater accumulation of Na. The apparent concentration of Na in the xylem stream was 44 times lower into the younger leaf 4 than into the older leaf 1. Exposure to NaCl (50 mol m−3) for 24 h elicited an increase in endogenous ABA in the oldest leaf only, but no significant changes occurred in the younger leaves

The Use of C-14-Ethane Diol as a Quantitative Tracer for the Transpirational Volume Flow of Water and an Investigation of the Effects of Salinity upon Transpiration, Net Sodium Accumulation and Endogenous ABA in Individual Leaves of Oryza-sativa-L

Oryza sativa L. (rice) seedlings growing in saline conditions exhibit pronounced gradients in leaf sodium concentration which is always higher in the older leaves than the younger ones. Individual leaf transpiration rates have been investigated to discover whether movement of sodium in the transpiration stream is able to explain these profiles from leaf to leaf. The use of 14C labelled ethane diol to estimate transpiration was evaluated by direct comparison with values obtained by gas exchange measurements. Ethane diol uptake was linearly related to the transpirational volume flow and accurately predicted leaf to leaf gradients in transpiration rate in saline and non-saline conditions. 14C-ethane diol and 22NaCl were used to compare the fluxes of water and sodium into different leaves. The youngest leaf showed the highest transpiration rate but the lowest Na accumulation in saline conditions; conversely, the older leaves showed the lower transpiration rates but the greater accumulation of Na. The apparent concentration of Na in the xylem stream was 44 times lower into the younger leaf 4 than into the older leaf 1. Exposure to NaCl (50 mol m-3) for 24h elicited an increase in endogenous ABA in the oldest leaf only, but no significant changes occurred in the younger leaves