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PubMed1997

A bone graft condensing syringe system for maxillofacial reconstructive surgery.

A new system of metallic syringes and pluggers specifically designed for delivery and condensation of particulate bone graft is reported, and the clinical application in maxillofacial reconstructive surgery is described. This bone graft condensing system has advantages over the conventional plastic injection syringes in enabling much better bone graft condensation as well as easier bone delivery and insertion of the syringe to the depth of the reconstruction crib.

Bone Transplantation↗

PubMed2003

Analysis of estrogenic activity of foodstuffs and cigarette smoke condensates using a yeast estrogen screening method.

Hormone mimics present in our environment are of concern because such agents could potentially reduce fertility and increase sexual dysfunction in wildlife and increase the risk of breast and reproductive organ cancers in man. Therefore, monitoring of the levels of estrogenic compounds in environmental materials is essential in order to prevent their exposure to man and to discover potential harmful effects on human health. In the present study, we analyzed estrogenic activity in 23 foodstuffs and cigarette smoke condensate samples extracted with an organic solvent, using the yeast estrogen screening (YES) system. Three soybean-related foodstuffs (soy sauce, tofu, miso), beer, coffee and cigarette smoke condensates showed clear estrogenic activity in the YES system. HPLC fractionations followed by the YES of these YES-positive samples revealed the presence of many estrogenic compounds in cigarette smoke condensates, whereas the other samples exerted estrogenic activities in only one or two fractions. Genistein was able to be isolated as the major active principle in soy sauce, tofu and miso, its concentration in these three foodstuffs ranging from 0.1 to 394 microg/g or ml. 8-Prenylnaringenin was also isolated from beer extracts as a major compound with estrogenic activity present at 0.22-4.0 ng/ml. Estrogenic activity of 8-prenylnaringenin with YES was 10-times as high as that of genistein, although it was 100-times less than that of 17beta-estradiol. Based on our results in vitro, 10 mg miso and 10 ml beer can be calculated to have similar estrogenic activity to 1 pmole 17beta-estradiol. It is very important that the effects of genistein and 8-prenylnaringenin on human health are elucidated.

Chromatography, High Pressure Liquid↗

PubMed2001

Partitioning of the Escherichia coli chromosome: superhelicity and condensation.

Segregation in Escherichia coli, the process of separating the replicated chromosomes into daughter progeny cells, seems to start long before the duplication of the genome reaches completion. Soon after initiation in mid-cell region, the daughter oriCs rapidly move apart to fixed positions inside the cell (quarter length positions from each pole) and are anchored there by yet unknown mechanism(s). As replication proceeds, the rest of the chromosome is sequentially unwound and then refolded. At termination, the two sister chromosomes are unlinked by decatenation and separated by supercoiling and/or condensation. Muk and Seq proteins are involved in different stages of this replication-cum-partition process and thus can be categorized as important partition proteins along with topoisomerases. E. coli strains, lacking mukB or seqA functions, are defective in segregation and cell division. The nucleoids in these mutant strains exhibit altered condensation and superhelicity as can be demonstrated by sedimentation analysis and by fluorescence microscopy. As the supercoiling of an extrachromosomal element (a plasmid DNA) was also influenced by the mukB and seqA mutations we concluded that the MukB and SeqA proteins are possibly involved in maintaining the general supercoiling activity in the cell. The segregation of E. coli chromosome might therefore be predominantly driven by factors that operate by affecting the superhelicity and condensation of the nucleoid (MukB, SeqA, topoisomerases and additional unknown proteins). A picture thus emerges in which replication and partition are no longer compartmentalized into separable stages with clear gaps (S and M phases in eukaryotes) but are parallel processes that proceed concomitantly through a cell cycle continuum.

Bacterial Outer Membrane Proteins↗

PubMed2002

Extensions of counterion condensation theory. I. Alternative geometries and finite salt concentration.

The counterion condensation theory originally proposed by Manning is extended to take account of both finite counterion concentration (m(C)) and the actual structure of the array of discrete changes. Counterion condensation is treated here as a binding isotherm problem, in which the unknown free volume is replaced by an unknown local binding constant beta', which is expected to vary with m(C) and polyion structure. The relation between the condensed fraction of counterion charge, r, beta' and m(C) is obtained from the relevant grand partition function via the maximum term method. In the case of the single polyion in a large salt reservoir, the result is practically identical to Manning's equation. In order to determine the values of beta' and r at arbitrary m(C), a second relation between r, beta' and m(C) is required. We propose an alternative auxiliary relation that is equivalent to previous assumptions near m(C) = 0, but which yields qualitatively correct and quantitatively useful results at finite m(C). Simple expressions for r vs. m(C) and beta' vs. m(C) are obtained by simultaneously solving the binding isotherm and auxiliary equations. Then r and beta' are evaluated for five different linear arrays of infinite extent with different geometries: (1) a straight line of charges with uniform axial spacing; (2) two parallel lines of in-phase uniformly spaced charges; (3) a single-helix of discrete charges with uniform axial spacing; (4) a double-helix of discrete charges with uniform axial spacing of pairs of charges; (5) a cylindrical array of many parallel charged lines, chosen to simulate a uniformly charged cylinder. In all cases, the computed binding isotherms exhibit qualitatively correct behavior. As m(C) approaches zero, r approaches the Manning limit, r = 1-1/(L(B)/b) where b is the average axial spacing of electronic charges in the array and L(B) is the Bjerrum length. However, beta' varies with polyion geometry, even in the zero salt limit, and matches the Manning value only in the case of a single straight charged line. With increasing m(C), r declines significantly below its limiting value whenever lambda(b) > or approximately equal 0.3, where lambda is the Debye screening parameter. In the case of cylindrical arrays containing either 2 or 100 parallel charged lines, r also decreases, whenever lambda(d) > or approximately equal 2.0, where d is the diameter of the array. In the case of two parallel charged lines, each with axial charge spacing b=3.4 A, which are separated by d = 200 A, r exhibits a plateau value, 0.76, characteristic of the two combined lines, when lambda(d)<<2.0, and declines with increasing m(C) to a shelf value, 0.52, characteristic of either single line, when lambda(d) > or approximately equal 2.0 and the lines become effectively screened from one another. beta' behaves in a roughly similar fashion. In the case of a cylindrical array of charged lines with the diameter and linear charge density of DNA, the r-values predicted by the present theory agree fairly well with those predicted by non-linear Poisson-Boltzmann theory up to 0.15 M uni-univalent salt.

Ions↗

PubMed1997

Skin carcinogenicity of condensed asphalt roofing fumes and their fractions following dermal application to mice.

Condensed roofing asphalt fumes, generated at 316 degrees C, were collected by cold trap condensation and fractionated by preparative high performance liquid chromatography. Chemical classes in each of the fractions (A-E) were identified by gas chromatography/mass spectroscopy. The fractions, various combinations of fractions, the raw and heated asphalt, the neat asphalt fume and the reconstituted asphalt were tested for carcinogenicity, and three fractions were tested for cocarcinogenicity and tumor promotion with benzo[a]pyrene (BaP). The skin application carcinogenesis bioassay was conducted by twice weekly application of test materials in 0.05 ml of acetone/cyclohexane (1:1) for 104 weeks to 40 groups of male C3H/HeJ mice (30/group). Fractions were applied at a mass in proportion to their amount in the neat asphalt fumes. In addition, the neat asphalt fume was tested on Sencar mice to determine if this strain was more susceptible to the carcinogenic effects of the fumes. Condensed neat asphalt fumes produced similar and statistically significant increased tumor yields of papillomas and carcinomas in both strains as compared to respective vehicle controls. Recombination of all fractions resulted in a tumor response similar to neat asphalt fumes. Among individual fractions, C was most potent, followed by B. The other single fractions were without significant tumorigenic activity. Combinations containing fractions B and C were most active among the mixtures that were assayed and no evidence of enhancement of tumorigenesis in the mixtures was found. No significant cocarcinogenic or tumor promoting activity was observed with fractions A, D, or E and BaP. Raw unheated asphalt produced a few tumors in C3H mice, but no tumors were seen when raw asphalt heated to 316 degrees C, with the fumes permitted to escape, was applied.

Animals↗

PubMed2003

Efficient synthesis of glyceroyl beta-lactoside and its derivatives through a condensation reaction by cellulase.

Condensation reaction between lactose and glycerol was effectively catalyzed by utilizing a commercially available cellulase preparation from Trichoderma reesei. The enzyme induced the formation of 1-O-beta-lactosyl-(R,S)-glycerol (1) and 2-O-beta-lactosyl glycerol (2) in a molar ratio of 7:3 and in a 20% yield based on lactose added. The enzyme also induced the condensation of lactose with 1,3-propanediol to produce O-beta-lactosyl propanediol (3) in a yield of 15%. When various alkanols (N: 2-8) and allyl alcohol were used in the condensation reaction, the corresponding alkyl and allyl beta-lactoside were obtained in the yields of 0.9-3.8% of the desired compounds.

Cellulase↗

PubMed1985

Nuclear chromatin condensation of mouse lymphoma (L-1210) cells by methylnitrosourea. An electron microscopic and biochemical study.

When the mouse lymphoma (L-1210) cells are treated with methylnitrosourea (MNU) at 37 degrees C for 30 min and then cultured for 4 h in a normal medium nuclear structure and functions of the cells are changed. We have investigated the mechanism as to how nuclear structure and functions are changed by MNU. In MNU-treated cells euchromatin area diminishes and chromatin condensation occurs. [3H]thymidine and [3H]uridine uptakes of the MNU-treated cells decrease. In contrast, when the MNU-treated cells are cultured in the presence of 3-aminobenzamide, a specific inhibitor of poly(ADP-ribose) synthetase changes of nuclear structure do not appear. [3H]Thymidine and [3H]uridine uptakes are partially and almost completely recovered, respectively. Autoradiographs of the cells labelled with [3H]NAD, a substrate of poly(ADP-ribose) synthetase show that silver grains due to [3H]ADP-ribose are densely located only in the cells where chromatin condensation occurs. Chromatin-bound proteins of molecular masses 20-25 X 10(3) daltons are specifically poly(ADP-ribosyl)ated in the MNU-treated cells. These results suggest that MNU-induced chromatin condensation is caused by poly(ADP-ribosyl)ation of chromatinbound proteins.

Animals↗

PubMed2001

Pattern classification by a condensed neural network.

Neural networks have come to the fore as potent pattern classifiers. More amenable to parallel computation, they are much faster than the nearest neighbor classifier (NN), which, however, has distinctly outperformed them in several applications. The purpose of this study is to investigate a condensed neural network that combines the classification speed of neural networks and the low error rate of the nearest neighbor classifier. This condensed network is a fast, accurate classifier of simple architecture and function: it consists of a set of generalized perceptrons that draw maximal hyperspherical boundaries centered on patterns of memory units, each circumscribing reference patterns of a single category. The generalized perceptrons carry out classification, assisted by sporadic nearest neighbor matching to patterns of a small reference set. We compare the condensed network to a high performance neural network pattern classifier (Kohonen) and to NN in experiments on hand-printed character recognition.

Neural Networks, Computer↗

PubMed1986

The technique of premature chromosome condensation to study the leukemic process: review and speculations.

The technique of premature chromosome condensation involves the fusion of mitotic cells with interphase cells resulting in the immediate condensation of the interphase chromatin into discrete chromosome units, the prematurely condensed chromosomes (PCC). The ability to visualize the interphase chromosomes of bone marrow and blood cells by this technique has proved useful in the study of human leukemia. This article describes how the PCC technique has been used to predict clinical outcome as well as gain insight into the biology of leukemia.

Chromatin↗

PubMed2004

Vibrational spectroscopic studies in the hydrolysis and condensation of chlorotrimethylsilane.

Raman and infrared spectroscopy were used to study the hydrolysis and condensation of chlorotrimethylsilane (CTMC) in aqueous organic solvents. From the recorded spectra and their intensity variation with time, we were able to identify trimethylsilanol as the reaction intermediate or the hydrolysis product as well as hexamethyldisiloxane (HMDS) as the final condensation product. The measured Raman intensity of CTMS at different time revealed that hydrolysis of CTMS is first order in terms of the CTMS concentration. From the Raman spectra collected under different conditions, it was noted that condensation reaction rates is faster in neutral condition than in acidic condition.

Hydrolysis↗

PubMed2003

Calyculin A causes the activation of histone H1 kinase and condensation of chromosomes in unfertilized sea urchin eggs independently of the maturation-promoting factor.

Calyculin A is known to inhibit the type-1 and type-2A phosphatases. We previously reported that calyculin A induces contractile ring formation in unfertilized sea urchin eggs, an increase in histone H(1) kinase activity, and chromosome condensation in the calyculin A-treated unfertilized eggs, and the changes induced by calyculin A are not affected by emetine, an inhibitor of protein synthesis. These observations suggest that the mechanism by which histone H(1) kinases are activated by calyculin A is different from that of maturation-promoting factor (MPF), which is activated by a molecular modification of existed cdc2 and newly synthesized cyclin B. We report here that no cyclin B was detected by immunoblotting of unfertilized calyculin A-treated eggs. In addition, no DNA synthesis was induced by calyculin A. As well, butyrolactone I (an inhibitor of cdc2 and cdk2 kinase) had no effect on the increase in histone H(1) kinase activity nor the chromosome condensation, both of which were induced by calyculin A. Thus, we conclude that calyculin A induces histone H(1) phosphorylation in an MPF-independent manner through inhibition of type-1 phosphatase, and that the chromosome condenses as a result of histone H(1) phosphorylation.

4-Butyrolactone↗

PubMed2003

Elemental and ion composition of exhaled air condensate in cystic fibrosis.

BACKGROUND: In cystic fibrosis (CF) the exact ion composition of the airway surface fluid is still debated and it is not clear if it differs from healthy subjects. The air that we exhale contains small droplets, which are generated by shear forces from the airway surface fluid and very likely mirror its ion composition. We hypothesized that differences between CF-patients and healthy controls would be reflected by differences in their exhaled air. METHODS: In nasally collected exhaled breath condensate from 20 children and young adults with cystic fibrosis and 20 healthy subjects, the elements and anions were determined by optical emission spectroscopy and ion-exchange chromatography. RESULTS: The concentrations of the major components Na and Cl- did not differ, Zn was higher and NO3- was lower in CF-patients. During a given time period, CF-patients produced a slightly larger volume of breath condensate and they exhaled more Na, K and Zn. Fluoride was detected in half of all samples, whereas copper, iron, magnesium, phosphorus and sulfur were present only sporadically, with no differences. CONCLUSIONS: These data detail the composition of exhaled breath condensate and suggest a similar Na and Cl- concentration in CF-airway surface fluid as in healthy subjects.

Adolescent↗

PubMed2006

[Analysis of oxidative stress in exhaled breath condensate from patients with severe pulmonary infections].

OBJECTIVE: Oxidative stress is an intrinsic part of the chain of events leading to inflammation of the airways caused by bacterial infection. The aim of this study was to determine whether analysis of exhaled breath condensate from patients with severe lung infections reveals changes in the redox state at the airway surface. PATIENTS AND METHODS: The study included a total of 48 subjects divided into 4 groups: individuals without respiratory disease (n=14), patients with multilobar pneumonia (n=13), patients who had chronic obstructive pulmonary disease with superinfection (n=14), and mechanically ventilated patients with severe pneumonia (n=7). A sample of exhaled breath condensate was obtained within the first 72 hours of hospital admission and the concentrations of nitrite, nitrate, 8-isoprostane, and myeloperoxidase (MPO) were determined. RESULTS: Significant differences in the concentrations of nitrite, 8-isoprostane, and MPO were observed between patients and individuals without respiratory disease but no differences were found between the 3 patient groups. The concentration of MPO was correlated with the concentrations of 8-isoprostane and nitrate, which were normalized to the nitrite concentration. CONCLUSIONS: Analysis of the concentrations of 8-isoprostane and MPO in exhaled breath condensate allows assessment of oxidative stress in the airways of patients with severe lung infections.

Adult↗

PubMed2003

1(2)41Aa, a heterochromatic gene of Drosophila melanogaster, is required for mitotic and meiotic chromosome condensation.

Genetic and cytological approaches have yielded significant insight into the mapping and organization of genes located in the heterochromatin of Drosophila melanogaster. To date, only a few of these genes have been molecularly characterized in detail, and their function unveiled. As a further step towards the identification of heterochromatic gene functions, we have carried out a cytological analysis of mitotic and meiotic cell divisions in mutants carrying different allelic combinations of 1(2)41Aa, a gene located in the proximal heterochromatin of chromosome 2. Our results showed that larval brains of 1(2)41Aa mutants display a high frequency of cells with irregularly condensed chromosomes. In addition, defective chromosome condensation was detected in male meiosis, consequently affecting chromosome segregation and giving rise to irregular spermatids. Taken together, these findings indicate that 1(2)41Aa is a novel cell cycle gene required for proper chromosome condensation in both somatic and germ line cells.

Animals↗

PubMed2000

Analysis of sulfonated naphthalene-formaldehyde condensates by ion-pair chromatography and their quantitative determination from aqueous environmental samples.

An ion-pair solid-phase extraction (IPE), ion-pair chromatography (IPC) procedure with fluorescence detection for the quantitative analysis of sulfonated naphthalene-formaldehyde condensates (SNFC) was developed, which provides full resolution of SNFC up to a degree of condensation n = 5 and partial resolution up to n = 15. Liquid chromatography-electrospray ionization-mass spectrometry confirmed that SNFC elute in the order of condensation. Response factors in fluorescence detection proved to be mass-constant, thereby allowing us to determine total SNFC amounts. With this IPC method, the weight- and the number-average molecular weights of these high-volume production chemicals (kiloton per annum), used as synthetic tanning agents, concrete plasticizers, and dispersants, can be determined. Recoveries in IPE range from 73 to 85% in river Rhine water and from 79 to 93% in tap water for n = 2 to n = 7 with limits of detection of 3-8 ng/L for individual homologues from 500 mL of water. The IPE-IPC procedure was applied to samples of secondary industrial effluents, river Rhine water, a river bank filtrate, and a groundwater sample. SNFC up to n = 6 were detected in the treated effluents. Total concentrations ranged from 208 micrograms/L in a secondary treated SNFC production effluent to < 1.4 micrograms/L in groundwater. These first analyses suggest a widespread occurrence of the lower oligomers of SNFC in the aquatic environment.

Chromatography, Liquid↗

PubMed2002

Matrix addition by condensation for matrix-assisted laser desorption/ionization of collected aerosol particles.

Condensation of an ultraviolet absorbing liquid matrix onto aerosol particles was used to enhance the ionization efficiency of large molecules. Laboratory-generated particles were coated with matrix, deposited on a sample target, and analyzed by laser desorption mass spectrometry with no other matrix addition. The aerosol was generated in a Collison nebulizer, and the particles were dried in a diffusion dryer before entering a heated region saturated with the liquid matrix 3-nitrobenzyl alcohol (NBA) and then entering a cooled condensation region. Matrix-coated particles were collected on a sample target and analyzed using a 337-nm laser and a time-of-flight mass spectrometer. Particles containing the peptides gramicidin S and gramicidin D were analyzed both with and without the matrix addition step. Condensation addition of matrix increased the biomolecule ion signal and resulted in mass spectra with less fragmentation and low-mass ion interference.

Aerosols↗

PubMed2000

Determination of condensed tannin monomers in environmental samples by capillary gas chromatography of acid depolymerization extracts

A method for molecular-level quantification of condensed tannin is described that uses acid depolymerization and carbocation capture by phloroglucinol. Resulting monomers and phloroglucinol adducts are trimethylsilyl derivatized, separated by capillary gas chromatography, detected by flame ionization, and quantified relative to standards. Optimal depolymerization conditions were determined for acid strength, phloroglucinol concentration, time, and temperature. The method gives reproducible results in leaf litter that are linear over 2 orders of magnitude with detection limits down to approximately 100 ng condensed tannin. In addition to tannin, triterpenoids were also identified and can be quantified with this method. Analyses of soils and sediments indicate that mineral interactions with condensed tannin are important both analytically and environmentally.

Journal Article↗

PubMed1992

DNA packaging induced by micellar aggregates: a novel in vitro DNA condensation system.

Evidence for a conceptually novel DNA packaging process is presented. X-ray scattering, electron microscopy, and circular dichroism measurements indicate that in the presence of positively charged micellar aggregates and flexible anionic polymers, such as negatively charged polypeptides or single-stranded RNA species, a complex is formed in which DNA molecules are partially embedded within a micellar scaffold and partially condensed into highly packed chiral structures. Based on studies of micelle-DNA and micelle-flexible anionic polymer systems, as well as on the known effects of a high charge density upon the micellar organization, a DNA packaging model is proposed. According to this model, the DNA induces the elongation of the micelles into rodlike aggregates, forming a closely packed matrix in which the DNA molecules are immobilized. In contrast, the flexible anionic polymers stabilize clusters of spherical micelles which are proposed to effect a capping of the rodlike micelles, thus arresting their elongation and creating surfactant-free segments of the DNA that are able to converge and collapse. Thus, unlike other in vitro DNA packaging systems, in which condensation follows encounters between charge-neutralized DNA molecules, a prepackaging phase where the DNA is immobilized within a matrix is proposed in this case. Cellular and nuclear membranes have been implicated in DNA packaging processes in vivo, and negatively charged polyelectrolytes were shown to be involved in the processes. These observations, combined with the basic tenets of the DNA condensation system described here, allow for the progression to the study of more elaborate model systems and thus might lead to insights into the nature and roles of the intricate in vivo DNA-membrane complexes.

Circular Dichroism↗