Familial Occurrence of Multiple Sclerosis with Thyroid Disease and Systemic Lupus Erythematosus

Multiple sclerosis (MS) has some features which suggest it is an autoimmune disease. Autoimmune diseases frequently occur in families, and patients and families often have more than one type of autoimmune disease. However, there are few reports of MS occurring in patients or families with other autoimmune conditions. It is difficult to make a separate diagnosis of MS in a patient who has a systemic autoimmune disease such as systemic lupus erythematosus (SLE) or Sjogren's syndrome, because these diseases can affect the nervous system directly. However, it is possible to make independent diagnoses of MS and an autoimmune disease confined to another single organ in the same patient, or diagnoses of MS and SLE (or other autoimmune diseases) in different family members. Here we describe clinically definite MS in 2 sisters, one of whom had Graves' disease, and the other of whom had a daughter with SLE and with a high titre of anti-thyroid antibodies. Other female family members over 4 generations had histories of thyroid disease, MS and Addison's disease. Available family members were HLA typed. The MS patients were positive for HLA DR2. All but one of the affected family members were related to the proband on the maternal side, and all of these affected females shared an HLA haplotype. However, this haplotype was also present in unaffected individuals. Thus HLA type alone cannot account for the familial occurrence of these disorders. We conclude that, in this family, MS, like autoimmune thyroid disease and SLE, may be an autoimmune disease developing in genetically predisposed individuals

Integration of hydraulic and chemical signalling in the control of stomatal conductance and water status of droughted plants.

We describe here an integration of hydraulic and chemical signals which control stomatal conductance of plants in drying soil, and suggest that such a system is more likely than control based on chemical signals or water relations alone. The determination of xylem [ABA] and the stomatal response to xylem [ABA] are likely to involve the water flux through the plant. (1) If, as seems likely, the production of a chemical message depends on the root water status (Ψr), it will not depend solely on the soil water potential (Ψs) but also on the flux of water through the soil-plant-atmosphere continuum, to which are linked the difference between Ψr and Ψs. (2) The water flux will also dilute the concentration of the message in the xylem sap. (3) The stomatal sensitivity to the message is increased as leaf water potential falls. Stomatal conductance, which controls the water flux, therefore would be controlled by a water-flux-dependent message, with a water-flux-dependent sensitivity. In such a system, we have to consider a common regulation for stomatal conductance, leaf and root water potentials, water flux and concentration of ABA in the xylem. In order to test this possibility, we have combined equations which describe the generation and effects of chemical signals and classical equations of water flux. When the simulation was run for a variety of conditions, the solution suggested that such common regulation can operate. Simulations suggest that, as well as providing control of stomatal conductance, integration of chemical and hydraulic signalling may also provide a control of leaf water potential and of xylem [ABA], features which are apparent from our experimental data. We conclude that the root message would provide the plant with a means to sense the conditions of water extraction (soil water status and resisance to water flux) on a daily timescale, while the short-term plant response to this message would depend on the evaporative demand

Measuring the photoelectron emission delay in the molecular frame

If matter absorbs a photon of sufficient energy it emits an electron. The question of the duration of the emission process has intrigued scientists for decades. With the advent of attosecond metrology, experiments addressing such ultrashort intervals became possible. While these types of studies require attosecond experimental precision, we present here a novel measurement approach that avoids those experimental difficulties. We instead extract the emission delay from the interference pattern generated as the emitted photoelectron is diffracted by the parent ion's potential. Targeting core electrons in CO, we measured a 2d map of photoelectron emission delays in the molecular frame over a wide range of electron energies. The measured emission times depend drastically on the emission direction and exhibit characteristic changes along the shape resonance of the molecule. Our approach can be routinely extended to other electron orbitals and more complex molecules