Bronchoalveolar lavage fluid protein composition in patients with sarcoidosis and idiopathic pulmonary fibrosis: a two-dimensional electrophoretic study

We used two-dimensional (2-D) electrophoresis to analyze the protein composition of fluid recovered by bronchoalveolar lavage (BALF) from patients with sarcoidosis and idiopathic pulmonary fibrosis, two forms of interstitial lung disease with different cellular composition and cytokine profile in BALF. They are also characterized by different pathogenesis and clinical evolution, idiopathic pulmonary fibrosis being less favorable than sarcoidosis due to rapidly progressive pulmonary fibrosis. Thirty-eight proteins or protein fragments, never previously assigned in BALF samples, were identified by various methods including mass fingerprinting of tryptic digests. Comparison of the BALF protein maps of the two groups of patients showed 32 spots with statistically significant disease-related variations in relative abundance. In sarcoidosis we found an increase in the amount of several plasma proteins, while in idiopathic pulmonary fibrosis we observed a statistically significant increase in low-molecular-weight proteins, many of which are involved in inflammatory processes (such as MIF and calgranulin) or antioxidant response (such as antioxidant peroxysomal enzyme and thioredoxin peroxidase 2). 2-D electrophoresis allowed us to identify new BALF proteins and to characterize protein composition in patients with sarcoidosis and idiophatic pulmonary fibrosis. Comparison of the gels of the two diseases showed that they differ in BALF protein profiles as they do in type of immune response.     

Moderate-resolution two-photon spectrum of the naphthalene crystal and naphthalene in durene

The two-photon absorption spectra at ～ 5 cm^?1 resolution are presented for the naphthalene crystal and naphthalene in durene at 2°K in polarized light. A rich vibronic spectrum of the ¹B_2u(3200 Å) naphthalene state is observed and some of the strongest vibronic origins are from in-plane vibrations.     

Time resolved fluorescence of anthracene in mixed crystals at 2K

An optical Kerr shuttered spectrograph has been used to time resolve the spontaneous fluorescence of aromatic mixed crystal systems at low temperature with moderate resolution. Transient effects on the fluorescence of anthracene in naphthalene excited with 614 cm^?1 vibrational excess energy in ¹B_2u have been observed that may signal measurable vibrational relaxation pathways. A model consistent with these observations is presented: it implicates a strong interaction between the intramolecular Franck—Condon and non-Franck—Condon modes in the relaxation process for specific excitation in the region of large excess lattice energy. Examination of the fluorescence for several aromatic systems integrated over the interval 0 to 30 ps following excitation high in the S₁ vibrational manifold failed to reveal evidence of non-Boltzmann vibrational distributions, although other largely unexplained effects have been observed.     

Two-dimensional infrared spectra of the 13C=18O isotopomers of alanine residues in an alpha-helix

The parameters needed to describe the two-dimensional infrared (2D IR) spectra of the isotopically labeled alpha-helix are presented. The 2D IR spectra in the amide-I' spectral region of a series of singly 13C=18O-labeled 25-residue alpha-helices were measured by three-pulse heterodyned spectral interferometry. The dependence of the spectra on the population time was measured. Individual isotopomer levels (residues 11-14) were clearly identified in 2D IR, downshifted by approximately 61 cm(-1) from the main helical band. By analyzing the line shapes of the 13C=18O diagonal peaks that appeared at approximately 1571.3 +/- 0.8 cm(-1) for all four labeled samples, we observed wider structural distributions for residues 14 and 11 than those for 12 and 13. A small fast component in the correlation function was used to estimate the dynamics of these distributions. In all cases, the v = 1 --> 2 transition showed a more Lorentzian-like line shape and also decayed faster than the v = 0 --> 1 transition, indicating that the population relaxation time of the v = 2 state was significantly faster than the v = 1 state. The amide transitions with naturally abundant 13C=16O appeared at approximately 1594 cm(-1), forming very weak and blurred cross-peaks with 13C=18O isotopomer modes. The effects of spectral interferences on the coherence time dependence of the detection frequency spectrum were also investigated. The methods of first moments and Wigner analysis were developed to circumvent the interference effects on the weak isotopomer transitions. The structural origin of the distributions for individual isotopomers was proposed to be an effect of nearby lysine residues on the intrahelical hydrogen-bond network.     

Direct observation of triplet state emission of single molecules: single molecule phosphorescence quenching of metalloporphyrin and organometallic complexes by molecular oxygen and their quenching rate distributions

Single molecules are detected through the phosphorescence emission of their triplet states. Emission of the triplet states of single molecules of Pt octabutoxycarbonyl porphyrin (PtOBCP) and ruthenium(II)-tris-4,7-diphenyl-1,10-phenanthroline dichloride (Ru(dpp)(3)Cl(2)) is reported. The single molecule phosphorescence is very sensitive to molecular oxygen. Each molecule has its own characteristic quenching rate by oxygen, and the distribution of these rates is measured for (Ru(dpp)(3)Cl(2)) on a quartz surface. The large variance of this distribution is presumed to be caused by fluctuations in the pseudobimolecular rate coefficient and the local oxygen concentration. The possibility of creating a quantitative single oxygen molecule sensor is suggested.     

Vibrational dynamics of N-H, C-D, and C=O modes in formamide

By means of heterodyned two-dimensional IR photon echo experiments on liquid formamide and isotopomers the vibrational frequency dynamics of the N-H stretch mode, the C-D mode, and the C=O mode were obtained. In each case the vibrational frequency correlation function is fitted to three exponentials representing ultrafast (few femtoseconds), intermediate (hundreds of femtoseconds), and slow (many picoseconds) correlation times. In the case of N-H there is a significant underdamped contribution to the correlation decay that was not seen in previous experiments and is attributed to hydrogen-bond librational modes. This underdamped motion is not seen in the C-D or C=O correlation functions. The motions probed by the C-D bond are generally faster than those seen by N-H and C=O, indicating that the environment of C-D interchanges more rapidly, consistent with a weaker C-D...O=C bond. The correlation decays of N-H and C=O are similar, consistent with both being involved in strong H bonding.     

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Comment on “fluorescence from an upper singlet of aromatic c-nitroso compounds”

Nitrosobenzene does not exhibit anomalous fluorescence from the S₂ state. It is shown how Raman scattering from the solvent can be used as an internal standard to determine very small fluorescence quantum yields.