Quantitative correlation between cardiovascular and plasma epinephrine response to mental stress

To investigate the quantitative correlations between cardiovascular and endogenous catecholamine response to mental stress, we gave a mental arithmetic test to 20 young healthy men. A direct and non-invasive haemodynamic measurement was performed by serial M-mode echocardiography. Heart rate, blood pressure, cardiac output, stroke volume, ejection fraction, left ventricular end-systolic pressure-volume ratio and plasma epinephrine increased over the baseline period during the test. The peripheral resistance and left ventricular end-systolic volume decreased, whereas left ventricular end-diastolic volume and plasma norepinephrine were unaltered. Furthermore, the degree of change in each haemodynamic parameter showing significant reaction, was well correlated with that of the increase in plasma epinephrine. The data suggest that acute mental stress induces endogenous epinephrine secretion resulting in a beta-adrenergic activated state in the cardiovascular system, namely, positive chronotropism, positive inotropism and vasodilatation.     

Immunoglobulin secreting cells in lymphocytes of patients with IgA deficiency or hyper-IgA

To assess the ability of immunoglobulin production in vivo, we enumerated the immunoglobulin secreting cells in the peripheral blood of patients with an IgA deficiency and of those with hyper-IgAemia. All seven patients with primary IgA deficiency and two of the three patients with secondary IgA deficiency had low numbers of IgA secreting cells. In all five patients with hyper-IgA the number of IgA secreting cells was increased. Our results suggest that measurement of immunoglobulin secreting cells in PBMCs is useful in the assessment of ability of immunoglobulin production in vivo.Abbreviations PBMCs peripheral blood mononuclear cells - MEM minimum essential medium - PFC plaque forming cells - VH immunoglobulin heavy chain variable region - CH immunoglobulin heavy chain constant region     

Molecular Basis of Disease Resistance Acquired through Cold Acclimation in Overwintering Plants

Plants require substantial resistance against freezing and pathogens for overwintering. These two traits are acquired through cold acclimation. In contrast to freezing tolerance, molecular basis of disease resistance acquired through cold acclimation is poorly understood. Recent studies have suggested that pathogenesis-related (PR) proteins that are secreted into the apoplast during cold acclimation are responsible for the disease resistance. Interestingly, some of the cold-induced PR proteins display both antifungal and antifreeze activities, suggesting a dual function in protecting plants from overwintering stresses. The signaling pathway for cold-induced disease resistance is currently unknown but can be independent of pathogen-induced defense mechanisms.     

Inactivation of Photosynthetic Oxygen Evolution and Concomitant Release of Three Polypeptides in the Photosystem II Particles of Spinach Chloroplasts

Photosystem II particles having an oxygen evolution activityas high as 300 µmol mg^–1 chlorophyll hr ^–1were prepared from spinach chloroplasts using Triton X-100.The oxygen evolution system in these particles was stable; 70%of the original activity remained after storage of the particlesat 0?C for 7 days. When the particles were treated at pH 9.3,the oxygen evolution was specifically inactivated and threepolypeptides having apparent molecular weights of 32,000. 24,000and 15,000 were simultaneously released. This observation suggeststhat these polypeptides are associated with the oxygen evolutionsystem of photosynthesis. ¹ Present address: Department of Chemistry, Faculty of Science,Toho University, Miyama 2-2-1, Funabashi, Chiba 274, Japan. (Received January 4, 1982; Accepted February 19, 1982)     

Metabolic effects of 3'-deoxyadenosine (cordycepin) and 2-halo-3'-deoxyadenosine on repair of X-ray-induced potentially lethal damage in Chinese hamster V79 cells

Using cultured Chinese hamster V79 cells, an attempt has been made to examine the phosphorylation of cordycepin and its 2-halo derivatives (2-chloro-3'-deoxyadenosine, 2-bromo-3'-deoxyadenosine, and 2-iodo-3'-deoxyadenosine) by adenosine kinase, within the cells, and to correlate it with their cytotoxicities and abilities to inhibit the repair of X-ray-induced potentially lethal damage (PLDR). Of all compounds, only cordycepin was found to be phosphorylated and showed both potent cytotoxicity and ability to inhibit PLDR.