Evaluation of glycogen level in human lung carcinoma tissues by an infrared spectroscopic method

Extensive mapping studies for seven antigen-antibody interactions have been carried out using both individual analogs and peptide libraries. With competitive ELISA, these studies have revealed that monoclonal antibodies exhibit a broad range of specificities, from antibodies that recognize only conservative substitutions for 1-2 positions of the antigenic determinant, to antibodies that recognize sequences that are completely unrelated to the parent antigen with comparable affinities. Synthetic combinatorial libraries, containing millions of peptide sequences, permit a more systematic and rapid evaluation of the extent of multiple-binding specificities of monoclonal antibodies than individual analogs. The peptide libraries used here comprise mixtures of compounds having specifically defined positions and mixture positions. The same diversity of sequences in different formats, which differ by the numbers of positions singularly defined and different locations defined within the sequence, can be examined. Comparison of the screening results, selection criteria of the most active mixtures, and different approaches used for the deconvolution of active individual compounds are discussed. Synthetic combinatorial libraries greatly facilitate the understanding of antigen-antibody interactions at the amino acid level and will assist in the development of improved immunodiagnostics.     

Investigation of graphite-like boron nitride by infrared spectroscopy

Translated from Poroshkovaya Metallurgiya, No. 2, pp. 73–77, February, 1991.     

钢中超低硫(<5μg/g)光谱与红外分析方法的研究

我国宽厚板冶炼钢种的硫成分一般小于5μg/g.为从时间上保证炉前、钢包、精炼冶炼过程成分的调控,需要采用光谱分析技术来检测这些过程的成分,而冶炼的成品试样则采用红外碳硫分析技术保证分析的精度.通过研究使冶炼的过程中的炉前、钢包、精炼试样全部采用光谱分析,成品试样能够在红外分析仪上检测.光谱仪分析超低硫的分析精度在1.5μg/g以下,红外分析仪分析超低硫的分析精度在0.4μg/g以下.     

Monitoring living tissues by electrical impedance spectroscopy

Solving the experimental difficulties associated with measurement of the electrical impedance of living tissues gives access to valuable tissue compartment parameters which are sensed within seconds using minimally invasive, simple metallic electrodes. Extracellular conductivity and cell membrane capacitance can be followed over time under conditions of metabolic toxicity, perfusion loss and thermal stress in liver, brain cortex, and muscle, respectively. Application of this technique in burns therapy allows an accurate estimation of the severity of thermal injury to skeletal muscle, supporting predictions on tissue survival.     

Protein structure in KBr pellets by infrared spectroscopy

The S14 ribosomal protein from the thermophilic organism Thermus thermophilus, which contains a zinc-finger-like motif, namely -C-X2-C-X12-C-X2-C- [Tsiboli, P. & Choli, T. (1995) Biol. Chem. Hoppe-Seyler 376, 127-130], has been overproduced, purified and investigated for its zinc content. According to atomic absorption experiments, the protein contains zinc at a molar ratio of one. Denaturation experiments with simultaneous use of denaturing and chelating agents (guanidine hydrochloride and EDTA), as well as renaturation experiments, have shown both that Zn is strongly bound to the protein and with 1:1 Zn/protein stoicheiometry. These findings provide very strong evidence in support of the participation of the zinc-finger motif and the Zn in the formation of a zinc-finger domain.     

Quality control in manufacturing process by near infrared spectroscopy

The combination of a pattern recognition technique with near infrared spectroscopy (NIR) to determine the conformity of a pharmaceutical mixture can be used in the routine checking of a pharmaceutical product. All the chemical and physical characteristics of the product that influence the NIR spectrum affect the qualification. The qualification is used to determine several deviations in the process: moisture, particle size and non-homogeneity. This work presents a method for the qualification analysis of a pharmaceutical mixture using the standard software of the instrument and a new program (DISPLOT). This program allows the acquisition of the plot of the scaled distances with its sign vs the wavelength.     

RNA-diethylstilbestrol interaction studied by Fourier transform infrared difference spectroscopy

Diethylstilbestrol (DES), a synthetic estrogen, is known to be a carcinogen in human and in animals. This study was designed to examine the interaction of DES with yeast RNA in aqueous solution at physiological pH with drug/RNA-phosphate (P) molar ratios of 1/80, 1/40, 1/20, 1/10, 1/4, and 1/2. Fourier transform infrared (FTIR) difference spectroscopy was used to determine the drug binding mode, the binding constant, the sequence selectivity, and RNA secondary structure in the RNA.DES complexes. Spectroscopic evidence showed that at low drug concentration (1/80 and 1/40), DES is intercalating through both Gua-Cyt and Ade-Urd base pairs with minor interaction with the backbone PO2 group (external binding). The calculated binding constant of K approximately 8.5 x 10(4) M-1 at a drug concentration of 3.12 x 10(-4) M shows that DES is a weaker intercalator than those of the methylene blue, acridine orange, and ethidium bromide. At high drug content (r > 1/40, where r represents the DES/RNA-phosphate molar ratio), a partial helix destabilization occurs with no alteration of RNA conformation upon drug complexation. However, a comparison with DNA.DES complexes showed that drug intercalation causes major reduction of the B-DNA structure in favor of A-DNA with no participation of the backbone PO2 group in the DES. DNA complexation.     

Reconstitution of bacteriorhodopsin from the apoprotein and retinal studied by Fourier-transform infrared spectroscopy

The reconstitution of the retinal-containing protein bacteriorhodopsin (BR) from the apoprotein and retinal has been studied by Fourier-transform infrared (FTIR) difference spectroscopy. 9-cis-Retinal which occupies the binding site but does not reconstitute the chromophore was used as "caged retinal". Photoisomerization to the all-trans isomer triggers the reconstitution reaction. Absorption bands in the FTIR difference spectra of the educt and product of the reaction could be assigned by comparison with a 9-cis-retinal FTIR spectrum or an FT-Raman spectrum of BR and due to band shifts observed upon deuterium exchange. Specific difference bands were assigned to the protonated carboxyl groups of D96 and D115 by use of the mutants D115N and D96N. Both aspartic acids are protonated also in the apoprotein with pKa values above 10 and undergo a frequency shift toward higher wavenumbers indicating a more hydrophobic environment in the reconstituted protein. No indication was found for protonation changes of carboxyl groups or other protonatable residues when carrying out the reaction at pH values between 4 and 10. The pH-dependent protonation changes reported earlier [Fischer & Oesterhelt (1980) Biophys. J. 31, 139-146] therefore may be caused by protons in a hydrogen-bonded network. Mutations of E204, but not of D38 or E9, cancel proton uptake during reconstitution at high pH as well as proton release at low pH. It is concluded, that E204, without changing its protonation state itself, is part of a protonatable hydrogen-bonded network which changes its pKa during reconstitution thereby causing the observed protonation changes.     

Total radiated power, infrared output, and heat generation by cold light sources at the distal end of endoscopes and fiber optic bundle of light cables

The differential diagnosis of the rupture of flexor pollicis longus tendon and profundus tendon to index finger to the interosseus anterior nerve syndrome can be difficult and can lead to misinterpretation of the clinical impression. Two cases are reported to demonstrate this problem. In the first case a spontaneous rupture of flexor pollicis longus was found, when first an interosseus anterior nerve syndrome was suspected. In a second case surgical exploration of flexor pollicis longus tendon and profundus tendon to index finger was done on the assumption of a rupture, that revealed intact tendons. In a second operation neurolysis of the interosseus anterior nerve was carried out with full recovery of flexion of the thumb and index finger.     

Rapid and reliable identification of food-borne yeasts by Fourier-transform infrared spectroscopy

Computer-based Fourier-transform infrared spectroscopy (FT-IR) was used to identify food-borne, predominantly fermentative yeasts. Dried yeast suspensions provided the films suitable for FT-IR measurement. Informative windows in the spectrum were selected and combined to achieve optimal results. A reference spectrum library was assembled, based on 332 defined yeast strains from international yeast collections and our own isolates. All strains were identified with conventional methods using physiological and morphological characteristics. In order to assess identification quality, another 722 unknown yeast isolates not included in the reference spectrum library were identified both by classical methods and by comparison of their FT-IR spectra with those of the reference spectrum library. Ninety-seven and one-half percent of these isolates were identified correctly by FT-IR. Easy handling, rapid identification within 24 h when starting from a single colony, and a high differentiation capacity thus render FT-IR technology clearly superior to other routine methods for the identification of yeasts.     

Urea denaturation of staphylococcal nuclease monitored by Fourier transform infrared spectroscopy

Hepadnavirus invasion in woodchucks has been identified as a potent inducer of autoantibodies against asialoglycoprotein receptor (anti-ASGPR), a molecule essentially unique to hepatocytes that mediate clearance of desialylated serum proteins. We evaluated the possible pathogenetic importance of anti-ASGPR triggered by woodchuck hepatitis virus (WHV), using anti-ASGPR-reactive serum immunoglobulins (Igs) from five animals with different stages of WHV hepatitis or self-limited WHV infection and isolated woodchuck hepatocytes or HepG2 cells as targets. The results revealed that WHV-induced anti-ASGPR can specifically inhibit asialoglycoprotein recognition by both homologous and heterologous liver cells, as tested in an asialofetuin (ASFN)-binding radioassay. However, the extent of the interference significantly varied (from 85% inhibition to none) for anti-ASGPR with similar titer from different animals, indicating a high degree of heterogeneity in the ASGPR epitope specificity and in the potential biological effects of these autoantibodies. The WHV-triggered anti-ASGPR also induced complement-mediated hepatocytolysis in a microculture tetrazolium (MTT) assay, which ranged from 8.9% +/- 0.3% to 33.6% +/- 3.6% (mean +/- SD) for different animals and target cell numbers. This cytopathic effect was strictly ASGPR-specific, complement-dependent, and was not related to the anti-ASGPR ability to inhibit ligand-hepatocyte binding. Our findings indicate that among pathways by which anti-ASGPR autoimmunity could cause liver damage, hepadnavirus-induced anti-ASGPR might impair hepatocytes by both disrupting clearance of desialylated proteins and activation of the complement-mediated cytolysis. These cytopathic effects might contribute to the pathogenesis, aggravate severity, and prolong recovery from liver injury in viral hepatitis.     

A new attenuated total reflectance Fourier transform infrared spectroscopy method for the study of proteins in solution

An attenuated total reflectance Fourier transform infrared method has been developed that allows collection of spectra from proteins in solution. This method eliminates any structural perturbations induced by the internal reflection element (IRE), and thus the spectra reflect the solution conformation of the protein. A key feature of the method is subtraction of the signal from any protein adsorbed to the IRE. The advantages of this method include the small amount of sample required and the high sampling rate. Attenuated total reflectance (ATR)-Fourier transform infrared spectroscopy (FTIR) is more versatile than transmission FTIR because it is possible to collect spectra of nontransparent samples, to use samples of very low protein concentration (< or = 0.3 mg/ml), and to study proteins in the presence of strongly absorbing solutes (such as denaturants). The experimental procedures and data processing routines developed were evaluated by collecting spectra from a set of 13 proteins and evaluating their accuracy with a partial least-squares analysis. The relative mean and standard deviation errors for the basis set analysis were 6.3% for alpha-helix, 5.9% for beta-sheet/extended structure, and 4.4% for turn, which are similar to values from comparable analyses of transmission FTIR spectra. In addition, a detailed comparison between this solution ATR method and the hydrated thin-film ATR technique is presented.     

Probing heart cytochrome c oxidase structure and function by infrared spectroscopy

IR spectra directly probe specific vibrators in bovine heart cytochrome c oxidase, yielding quantitative as well as qualitative information on structures and reactions at these vibrators. C-O IR spectra reveal that CO binds to Fe2+ a3 as two conformers each in isolated immobile environments sensitive to Fea and/or CuA oxidation state but remarkably insensitive to pH, medium, anesthetics, and other factors that affect activity. C-N IR spectra reveal that the one CN- that binds to fully and partially oxidized enzyme can be in three different structures. These structures vary in relative amounts with redox level, thereby reflecting dynamic electron exchange among Fea, CuA, and CuB with associated changes in protein conformation of likely significance in O2 reduction and H(+)-pumping. Azide IR spectra also reflect redox-dependent long-range effects. The amide I IR bands, due to C-O vibrators of peptide linkages and composed of multiple bands derived from different secondary structures, reveal high levels of alpha-helix (approximately 60%) and subtle changes with redox level and exposure to anesthetics. N2O IR spectra reveal that these anesthetic molecules at clinically relevant levels occupy three sites of different polarity within the enzyme as the enzyme is reversibly, but only partially, inhibited.     

Applications of infrared spectroscopy to medical biology

After an apparently new virus in the family Paramyxoviridae was isolated from pigs in August 1997, an investigation was carried out to assess its risk for humans. More than 250 persons with potential exposure to infected pigs were tested serologically. Two piggery workers with intense occupational exposure had high convalescent-phase antibody titers to this new virus. In early June 1997, both workers had an influenzalike illness with rash; serologic testing showed no alternative cause. Strong evidence indicates that the two men became ill from this new virus, but the mode of transmission from pigs to humans remains unknown.     

Conformation of phosphatidylserine in bilayers as studied by Fourier transform infrared spectroscopy

The 13C labeled lipid 1[1'-13C]DPPS-NH4+ and its metal salts were used to unambiguously assign all carbonyl vibrations in the infrared spectrum of phosphatidylserines. It is shown that the C=O stretching band at 1741 cm-1 of phosphatidylserines previously assigned to the sn-1 C = O vibration contains contributions from both the sn-1 and the sn-2 carbonyls. The C=O stretching band at frequencies between 1715 and 1730 cm-1 previously assigned to the sn-2 C=O vibration also contains contributions from both carbonyl groups. The frequency dependence observed with the ester carbonyls primarily reflects hydrogen bonding and the polarity of the immediate vicinity. Conformational changes are accounted for in terms of frequency shifts if the conformational change involves the disposition of the C=O groups and in turn the hydrogen bonding properties. The infrared spectra of phospholipids dispersed in aqueous medium in the liquid crystalline state are inconsistent with a simple phospholipid conformation, e.g., with a conformation as found in the single-crystal structure of 1,2-dimyristoyl-sn-phosphatidylcholine and 1,2-dilauroyl-rac-phosphatidylethanolamine. The spectra support the hypothesis proposed earlier (Hauser et al., Biochemistry, 1988) on the basis of existing single-crystal phospholipid structures and NMR evidence. The hypothesis states that several conformations are present in liquid crystalline phospholipid dispersions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cervical actinomycosis. A rare differential diagnosis of parotid tumor]

BACKGROUND: Allergic rhinitis is usually treated with oral antihistamines or nasal steroids. Topically active nasal antihistamine is a new treatment modality for allergic rhinitis. The efficacy in comparison to well established topical treatment alternatives is not fully known. OBJECTIVE: To compare the efficacy of intranasally administered azelastine to budesonide, at their respectively recommended dosage, on the symptoms of perennial rhinitis patients. METHODS: A placebo-controlled, randomized, parallel group study was conducted to compare the efficacy and tolerability of intranasal budesonide aqueous suspension (256 microg once daily) with azelastine hydrochloride nasal spray (280 microg twice daily (560 microg/day)) and with placebo in the treatment of perennial allergic rhinitis. The 195 patients (with at least a 2-year history of perennial allergic rhinitis) recorded individual nasal symptom scores, the degree of symptom control achieved and any adverse events experienced over a 2-week baseline period and a 6-week treatment period. RESULTS: Following treatment, the reductions in mean combined and individual nasal symptom scores from baseline values were significantly greater in the budesonide group compared with the placebo group (P < .0001 for all variables except runny nose P = .01). In patients treated with budesonide, there were also significantly larger reductions from baseline values in combined nasal symptom scores (P < .01) and in scores for all individual nasal symptoms (P < or = .05) compared with those treated with azelastine. The reductions from baseline in both combined and individual nasal symptom scores did not differ between azelastine and placebo. The study medications were well tolerated, producing no unexpected or serious treatment-related adverse events. CONCLUSION: A once-daily dose of 256 microg of intranasal budesonide aqueous suspension is significantly more effective at relieving the symptoms of perennial allergic rhinitis compared with a twice daily dose of 280 microg of azelastine nasal spray.