Circular dichroism in photoelectron angular distributions from two‐color (1+1) REMPI of NO

A detailed experimental and theoretical study of dichroic effects in photoelectron angular distributions is reported for (1+1), two‐color REMPI of NO via the A^ 2Σ^+, v=0 state. Optically aligned A state rotational levels are probed through ionization by circularly polarized light. Resultant photoelectron angular distributions exhibit significant left–right asymmetry, the phase and magnitude of which are shown to be related to the curvature of the excited state M_J distribution. Theoretical calculations involving a full ab initio treatment of the ionization dynamics result in circularly dichroic angular distribution (CDAD) parameters in good agreement with those derived experimentally. Additional effects including hyperfine depolarization and coherence are also discussed in relation to the observed CDAD data

A multiphoton ionization study of the photodissociation dynamics of the S_2 state of CH_3ONO

Two‐color (1+1) REMPI (resonantly enhanced multiphoton ionization) photoelectron spectroscopy is used to probe the NO photofragments produced by the UV photodissociation of methyl nitrite, i.e., CH_3ONO+hν→CH_3ONO∗(S_2)→CH_3O⋅(X)+NO(X, v, J). The photofragments are produced in their ground electronic states but with high rotational and translational energy. NO fragment angular distributions, rotational state distributions, and spatial alignment are determined by photoion and photoelectron detection. The initial state alignment is obtained by the CDAD (circularly dichroic angular distribution) technique for the first time. CDAD measurements for rotational levels with 35.5≤J≤46.5 result in alignment parameters at the classical high‐J limit of A^(2)_0 =−0.4. This alignment is consistent with an ‘‘impulsive’’ dissociation mechanism in which photofragment recoil along the CH_3O–NO bond imparts substantial rotational angular momentum to the NO molecule resulting in a high‐J state distribution and preferential rotation in the plane of dissociation. These measurements clearly establish the utility of the CDAD method for probing chemical processes in which spatial alignment plays an important role. Photoion angular distributions are used to probe correlations between the CH_3ONO transition dipole moment, NO fragment velocity, and angular momentum. These correlations reveal additional details of the photolysis mechanism

Cigarette Smoking Interferes With Treatment of Hypertension

• We retrospectively analyzed two studies to determine whether smoking affected the treatment of hypertension. In a study of the effects of propranolol hydrochloride (a hepatically metabolized β-blocker) vs hydrochlorothiazide, 108 smokers and 232 nonsmokers were randomized to the propranolol treatment group. The propranolol-treated smokers tended to be younger, taller, thinner, and were more likely to be black. This group also had an initial blood pressure reduction (± SD) of -7.9 ± 12.9/ -8.7 ± 8.4 mm Hg compared with -10.7 ± 13.0/ -10.9 ± 7.1 mm Hg for the nonsmokers. Blood pressure increased less during the one-year maintenance period for the nonsmokers. However, when analyzed by race, this effect was seen in blacks, but not in whites. Diastolic blood pressure tended to be reduced more in nonsmokers (vs smokers) receiving hydrochlorothiazide (-12.1 ± 6.7 vs -10.7 ± 6.7 mm Hg, respectively). The second study compared the effects of nadolol (a renally excreted β-blocker) with bendroflumethiazide. There were no significant effects on blood pressure for either of these drugs. In both studies, there was a greater tendency for smokers to be terminated from the study irrespective of drug group. We conclude that cigarette smoking does interfere with the treatment of hypertension in general, and especially with reduction of blood pressure by propranolol in black patients.(Arch Intern Med 1988;148:2116-2119

Cell autonomous role of iASPP deficiency in causing cardiocutaneous disorders

Desmosome components are frequently mutated in cardiac and cutaneous disorders in animals and humans and enhanced inflammation is a common feature of these diseases. Previous studies showed that inhibitor of Apoptosis Stimulating p53 Protein (iASPP) regulates desmosome integrity at cell–cell junctions and transcription in the nucleus, and its deficiency causes cardiocutaneous disorder in mice, cattle, and humans. As iASPP is a ubiquitously expressed shuttling protein with multiple functions, a key question is whether the observed cardiocutaneous phenotypes are caused by loss of a cell autonomous role of iASPP in cardiomyocytes and keratinocytes specifically or by a loss of iASPP in other cell types such as immune cells. To address this, we developed cardiomyocyte-specific and keratinocyte-specific iASPP-deficient mouse models and show that the cell-type specific loss of iASPP in cardiomyocytes or keratinocytes is sufficient to induce cardiac or cutaneous disorders, respectively. Additionally, keratinocyte-specific iASPP-deficient mice have delayed eyelid development and wound healing. In keratinocytes, junctional iASPP is critical for stabilizing desmosomes and iASPP deficiency results in increased and disorganized cell migration, as well as impaired cell adhesion, consistent with delayed wound healing. The identification of a cell autonomous role of iASPP deficiency in causing cardiocutaneous syndrome, impaired eyelid development and wound healing suggests that variants in the iASPP gene also may contribute to polygenic heart and skin diseases