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PubMed1988

Trabecular, nasal, branchial, and pericardial cartilages in the sea lamprey, Petromyzon marinus: fine structure and immunohistochemical detection of elastin.

Immunohistochemical and ultrastructural methods were used to examine the distribution of elastin and the fine structure of the trabecular, nasal, branchial, and pericardial cartilages in the sea lamprey, Petromyzon marinus. The cells and matrix, as well as the overall organization of these components, in larval and adult trabecular cartilage resemble those of adult annular and piston cartilages (Wright and Youson: Am. J. Anat., 167:59-70, 1983) Chondrocytes are similar to those in hyaline cartilage. Lamprin fibrils and matrix granules, but no collagen fibrils, are found in a matrix arranged into pericellular, territorial, and interterritorial zones. Branchial, pericardial, and nasal cartilages differ from trabecular, annular, and piston cartilages in the organization of their matrix and in the structural components of their matrix and perichondria. Furthermore, immunoreactive elastin-like material is present within the perichondria and peripheral matrices of nasal, branchial, and pericardial cartilages in both larval and adult lampreys. Oxytalan, elaunin, and elastic-like fibers are dispersed between collagen fibers in the perichondrium. The matrix contains lamprin fibrils, matrix granules, and a band of amorphous material, which is reminiscent of elastin, in the periphery bordering the perichondrium. The presence of elastic-like fibers and elastin-like material within some lamprey cartilages implies that this protein may have evolved earlier in vertebrate history than has been previously suggested.

Animals↗
PubMed2003

Analysis of high-density lipoprotein apolipoproteins recovered from specific immobilized pH gradient gel pI domains by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

The proteins associated with the circulating lipoproteins in the blood function not only for mediating lipid metabolism but also for maintaining structural stability of the micellelike structure. Any modifications of these proteins, by mutation or posttranslational modification, could compromise the function of these proteins and contribute to the development of cardiovascular disease. Because of the presence of extensive lipophilic domains, these proteins, when recovered from the lipoprotein particle (apolipoproteins) present an analytical challenge because of low solubility and proclivity toward aggregate formation. Our goal is to characterize these proteins by a combination of high-accuracy pI measurement coupled with MALDI analysis. In this report, we demonstrate the high resolution of immobilized pH gradient isoelectric focusing (IPG-IEF) for the analysis of these apolipoproteins isolated from serum HDL collected from a density gradient ultracentrifugation-based separation. The IPG separation of the HDL apolipoproteins was imaged and combined with digital analysis to produce a detailed pI profile of the apolipoproteins in the high-density lipoprotein (HDL) fraction. This is the first time that a high-resolution pI profile has been obtained for the HDL apolipoproteins. The feasibility of linking the pI profile to a MALDI-based molecular weight determination was achieved by incorporating passive elution of the intact proteins from the IPG gel with a four-component solvent mixture that solved the problem of recovery of the apolipoproteins from the IPG matrix. Twenty-five bands were observed in the pI profile. A survey analysis of 12 of these bands by MALDI indicated that they were associated with the known HDL apolipoproteins. While there is considerable overlap in the pI profiles of the apolipoproteins, linking the analysis with a MALDI-based second dimension in m/z is shown to be an efficient method to characterize this complex mixture of apolipoproteins.

Apolipoproteins↗
PubMed1999

An algorithm for the assembly of robust physical maps based on a combination of multi-level hybridization data and fingerprinting data.

We have developed an algorithm which combines data obtained from restriction digestion experiments and hybridization experiments to construct robust physical maps of whole chromosomes. The algorithm has been incorporated into a program which accepts hybridization data consisting of an unordered hybridization matrix and fingerprinting data containing band coordinates for each clone. The combined data is used to produce a non-redundant, ordered matrix which can be further reduced to represent a minimum tile coverage of the chromosome. In addition, the method also takes into account multi-level hybridization events which allows for an improved treatment of the hybridization data. The program is evaluated against several other contig building programs using simulated and real data sets. Finally, it is applied to construct a physical map of the 4.1 Mb genome of Ochrobactrum anthropi based on 1387 clones and 70 probes, as well as 624 fingerprints.

Algorithms↗
PubMed1996

Polarized FT-IR microscopy of calcified turkey leg tendon.

Polarized Fourier transform infrared microscopy (FT-IRM) was used to assess the orientation of mineral and matrix components of the normally calcified turkey leg tendon. Two groups of tendon, < 16 weeks of age (young) and > 60 weeks of age (old), were analyzed. Linear sequences from calcified, non-calcified, and transitional regions of the tendons were examined. Spectra collected in the "parallel polarization" mode were acquired with the electric vector of the infrared radiation parallel to the collagen fiber axis whereas spectra collected in the "perpendicular polarization" mode were acquired with the electric vector of the infrared radiation perpendicular to this axis. The v2 carbonate (850-890 cm-1) and v1, v3 phosphate (900-1180 cm-1) contours of the tendon mineral as well as the collagen amide I, II, and III bands of the extracellular matrix all displayed marked dichroism. The CO3(2-) ions substituted for PO4(3-) (878 cm-1, type B substitution) in the tendon mineral displayed parallel dichroism while the CO3(2-) ions substituted for OH (871 cm-1, type A substitution) in the tendon mineral displayed perpendicular dichroism. These orientational effects for both sites of carbonate substitution were greater in the older animals. The polarization properties of the v1, v3 phosphate contour were analyzed by use of an empirical anisotropy parameter (A), the value of which monitors the degree of orientation. This index significantly increased in the older animals indicating that aging produces a more highly oriented mineral. The amide I, II, and III contours of the collagen extracellular matrix also exhibited marked dichroism. The amide I component exhibits perpendicular dichroism while the amide II and III components exhibit parallel dichroism. The current study demonstrates the ability of polarized FT-IRM to assess the orientation of the mineral and matrix components of calcified tissue at the microscopic level.

Amides↗
PubMed2003

[Influence of transfected EGFR-cDNA on bcl-2 and Bax in glioblastoma cells].

OBJECTIVE: To investigate the correlation of bcl-2 and Bax protein with nuclear matrix in glioblastoma cell line U87 as well as the effect of EGFR-cDNA transfection on the expression of bcl-2 and Bax in U87 cells. METHODS: The correlation of bcl-2 and Bax protein with nuclear matrix in glioblastoma cell line U87 was studied by confocal microscopy and Western blot. The expression of bcl-2 and Bax in EGFR-cDNA transfected and untransfected glioblastoma cell lines was studied by Western blot. RESULTS: Confocal microscopic images showed that bcl-2 protein was localized in the periphery of the nuclear matrix and Bax in the nuclear matrix. A 26 kDa bcl-2 band and a specific band of Bax at about 66 000 were detected in nuclear matrix proteins by western blot. The expression of bcl-2 was lower but that of Bax was higher in EGFR-cDNA transfected cells than the control. CONCLUSION: Bcl-2 and Bax, being nuclear matrix associated proteins, are probably involved in the EGFR-cDNA induced malignant conversion of glioblastoma cells by introducing EGFR cDNA into the tumor cells.

Apoptosis↗
PubMed1979

Benign epithelioid cell nevi of the iris.

Two benign acquired melanocytic lesions of the iris stroma had distinctive clinical and pathologic features. One tumor was loculated and polypoid, suggesting ectopic glandular tissue, while the other was a flat tumor with a rich surface capillarity. Both lesions histologically were composed of mononucleated, binucleated, and multinucleated hypopigmented epithelioid and elongated "myoid" cells, widely separated in a finely fibrillar eosinophilic stroma. The ultrastructural features of one case included hyperconvoluted nuclei, conspicuous cytoplasmic filaments are rare, filamentary-striated (leptomeric) structures, scant organelles and inclusions except for numerous mitochondria and glycogen granules, small and infrequent melanosomes, and a fibrillary extracellular matrix focally organized into banded basement membrane material.

Adult↗
PubMed2002

Chlorine oxide radicals ClOx (x = 1-4) studied by matrix isolation spectroscopy.

Low pressure flash thermolysis of different precursor molecules containing-ClO, -ClO3 or -OClO3 yield, when highly diluted in Ne or O2 and subsequent quenching of the products in a matrix at 5 or 15 K, ClOx (x = 1, 3, 4) radicals, respectively. If Ne or O2 gas is directed over solid ClO2 at -120 degrees C and the resulting gas mixtures are immediately deposited as a matrix, a high fraction of (OClO)2 is trapped. This enables recording of IR and UV spectra of weakly bonded (OClO)2 dimers and detailed studying of their photochemistry. For Ne or O2 matrix isolated ClO radicals the vibrational wavenumbers and electronic transitions are only slightly affected compared with the gas phase. In this study strong evidence is found for long lived ClO in the electronically excited 2 [symbol: see text] 1/2 state. A comprehensive IR study of Ne matrix isolated ClO3 (fundamentals at 1081, 905, 567, 476 cm-1) yield i) a reliable force field; ii) a OClO bond angle of alpha e = 113.8 +/- 1 degrees and iii) a ClO bond length of 148.5 +/- 2 pm in agreement with predicted data from quantum chemical calculations. The UV/Vis spectrum of ClO3 isolated in a Ne matrix (lambda max at 32,100 and 23,150 cm-1) agrees well with the photoelectron spectrum of ClO3- and theoretical predictions. The origin of the structured high energy absorption is at 22,696 cm-1 and three fundamentals (794, 498, 280 cm-1) are detected in the C2E state. By photolysis of ClO3 with visible light the complex ClO.O2 with ClO in the 2 [symbol: see text] 1/2 state is formed. In an extended spectroscopic study of the elusive ClO4 radical, isolated in a Ne or O2 matrix, three additional IR bands, a complete UV spectrum and a strong interaction with O2 are found. This leads to the conclusion that ClO4 exhibits C2v or Cs symmetry with a shallow potential minimum and forms with O2 the previously unknown peroxy radical O3ClO-O2. All these results are discussed in the context of recent developments in the chemistry and spectroscopy of the important and interesting ClOx (x = 1-4) family of radicals.

Journal Article↗
PubMed1989

Effect of adriamycin on hamster molar tooth development in vitro: 1. Morphological changes.

The effect of adriamycin (1 mg/liter) on the development of the golden hamster 3-day-old second maxillary molars (M2) was investigated in vitro. Exposure of the molars to 1 mg/liter adriamycin during the first 2 hours of culture produced smaller teeth 3-7 days later, as determined by measurements of dry weights and by histological observations. Higher doses caused severe necrosis. The more differentiated pulp fibroblasts showed osteodentin formation 3 days after treatment with adriamycin (1 mg/liter), while the more immature ones underwent necrosis. The phenotypic changes brought on by the drug were permanent, and osteodentin continued to be formed throughout the course of this study. In addition the cervical loop region was inhibited from growing, while the production of the matrices of enamel and dentin appeared to be increased at 3 and 5 days after treatment. Electron microscopy of the forming osteodentin matrix revealed a random arrangement of banded collagen fibers during the early stage of osteodentin formation. As more matrix was formed, the collagen became quite compact and appeared quite similar to dentin. Finally, matrix vesicles were found among the collagenous matrix that was not yet mineralized. With the exception of the increased production of enamel and dentin, these in vitro results confirmed those earlier in vivo studies on the effect of adriamycin on rat incisor tooth.

Animals↗
PubMed2004

The fetal esophagus: anatomical and physiological ultrasonographic characterization using a high-resolution linear transducer.

OBJECTIVE: To study the sonographic anatomy and physiology of the human fetal esophagus during the mid-trimester of pregnancy using a high-resolution linear transducer. METHODS: This was a prospective observational study of the fetal esophagus between 19 and 25 weeks' gestation. The study was performed in 60 consecutive fetuses, after a normal anatomy scan, using a 5-13-MHz matrix array wide-band transducer. During the examination the collapsed esophagus was first visualized, and followed by a 5-min video recording in order to demonstrate luminal patency and peristaltic waves. RESULTS: Complete anatomical visualization of the esophagus was possible in 52 (86.7%) patients and at least partial visualization in 58 (96.7%) patients. Three different patterns of esophageal motility were observed: a simultaneous and short opening of the whole esophagus was found in 35 (58.3%) fetuses; a segmental, peristalsis-like movement from the pharynx, through the mediastinum, and into the stomach was found in 18 (30%) fetuses; and in one fetus reflux-like passage of solid contents from the stomach was observed. The mean time required for demonstration of esophageal patency was 96.1 (range, 10-300) s. CONCLUSIONS: Demonstration of normal anatomy and physiological activity of the fetal esophagus is feasible using appropriate transducers. The most commonly observed pattern of esophageal motility in the mid-trimester of pregnancy is the simultaneous relaxation of the upper and lower esophageal sphincters with concurrent opening of the esophageal lumen from the upper thorax to the stomach. Demonstration of a patent esophagus may be helpful in fetuses with suspected esophageal atresia.

Esophagus↗
PubMed1994

Infrared spectroscopy of Triton and Pluto ice analogs: the case for saturated hydrocarbons.

The infrared transmission spectra and photochemical behavior of various organic compounds isolated in solid N2 ices, appropriate for applications to Triton and Pluto, are presented. It is shown that excess absorption in the surface spectra of Triton and Pluto, i.e., absorption not explained by present models incorporating molecules already identified on these bodies (N2, CH4, CO, and CO2), that starts near 4450 cm-1 (2.25 micrometers) and extends to lower frequencies, may be due to alkanes (C(n)H2n+2) and related molecules frozen in the nitrogen. Branched and linear alkanes may be responsible. Experiments in which the photochemistry of N2:CH4 and N(2):CH4:CO ices was explored demonstrate that the surface ices of Triton and Pluto may contain a wide variety of additional species containing H, C, O, and N. Of these, the reactive molecule diazomethane, CH2N2, is particularly important since it may be largely responsible for the synthesis of larger alkanes from CH4 and other small alkanes. Diazomethane would also be expected to drive chemical reactions involving organics in the surface ices of Triton and Pluto toward saturation, i.e., to reduce multiple CC bonds. The positions and intrinsic strengths (A values) of many of the infrared absorption bands of N2 matrix-isolated molecules of relevance to Triton and Pluto have also been determined. These can be used to aid in their search and to place constraints on their abundances. For example, using these A values the abundance ratios CH4/N2 approximately 1.3 x 10(-3), C2H4/N2 < or = 9.5 x 10(-7) and H2CO/N2 < or = 7.8 x 10(-7) are deduced for Triton and CH4/N2 approximately 3.1 x 10(-3), C2H4/N2 < or = 4.1 x 10(-6), and H2CO/N2 < or = 5.2 x 10(-6) deduced for Pluto. The small amounts of C2H4 and H2CO in the surface ices of these bodies are in disagreement with the large abundances expected from many theoretical models.

Alkanes↗
PubMed1997

An electron microscopic study on the process of acid demineralization of cortical bone.

Demineralization has been shown to foster osteoinductive properties of cortical bone grafts, yet little is known about the process of demineralization and how to control it. The purpose of this study was to investigate the process of cortical bone demineralization by using scanning electron microscopy to evaluate how hydrochloric acid demineralizes cortical bone. Results showed that in the demineralization of diaphyseal cortical bone specimens using hydrochloric acid, a uniformly thick circumferential band of demineralized bone matrix surrounds an inner undecalcified bone core as the process of demineralization occurs. The interface between the demineralized and mineralized section of the bone specimens was extremely sharp. This interface between demineralized and undemineralized bone was noted to advance as a reaction front with increasing demineralization which resulted in continuous shrinkage of the inner cortical bone core. This study suggests that cortical bone demineralization can be best described using an advancing reaction front theory, and this explanation can be used for implementation of the concept of controlled demineralization.

Animals↗
PubMed2005

Topographical localisation of glucidic residues and their variations in the canine zona pellucida during folliculogenesis.

In the present ultrastructural study, horseradish peroxidase-labelled lectins, in conjunction with antiperoxidase antibody and protein A-gold, were used to characterise and localise the oligosaccharide sequences of zona pellucida glycoproteins at different stages of follicular development in the canine ovary. Deacetylation and sialidase digestion were also performed before lectin cytochemistry. The zona pellucida of oocytes present in unilaminar primary follicles reacts with WGA- and RCA-I-lectins. The zona pellucida of oocytes present in bilaminar and trilaminar secondary follicles displays positivity to WGA, RCA-I, Con-A, UEA-I, and sialidase/SBA. This labelling pattern persists in the zona pellucida of oocytes present in antral tertiary follicles with the exception of WGA and RCA-I reactive sites which are differently distributed throughout the zona pellucida. The topographical distribution of these carbohydrates is not uniform throughout the zona pellucida, indicating the regionalization of oligosaccharide chains within three concentric bands of the zona matrix: an inner surface close to the oocyte plasma membrane, an intermediate portion and an outer layer in contact with the follicular cells. Our results demonstrated variations in the presence and distribution of the carbohydrate residues in the canine zona pellucida during different stages of follicular growth. We also observed the presence of vesicles in both the ooplasm and granulosa cells, showing a similar lectin binding pattern to that of the zona pellucida.

Animals↗
PubMed1987

Juvenile renal disease in the Doberman Pinscher: ultrastructural changes of the glomerular basement membrane.

Ten cases of juvenile renal disease in Doberman Pinschers were examined by light microscopy and 8 of them additionally by electron microscopy. Two distinct basic ultrastructural lesions of the glomerular basement membrane (GBM) were observed. One is characterized by lamellation of the lamina densa with intramembranous focal areas of lucency containing electron-dense particles, the second by diffuse attenuation of the lamina densa with intramembranous and/or subendothelial deposition of matrix entrapping cross-banded fibres (collagen). Based on similar ultrastructural changes in other hereditary nephropathies in man and dogs, a metabolic or biochemical basis for the structural lesions is suspected.

Aging↗
PubMed2005

Spindle cell lipoma of the floor of the mouth: report of a case.

Spindle cell lipoma is a benign tumour composed by: (1) mature fat cells; (2) spindle cells; (3) a myxoid matrix separated by thick bands of birefringent collagen. Only 14 cases have been reported in the oral cavity. The authors present the second case located in the floor of the mouth. The treatment of the lesion consists of a local excision.

Humans↗
PubMed2006

Is photobleaching necessary for Raman imaging of bone tissue using a green laser?

Raman microspectroscopy is widely used for musculoskeletal tissues studies. But the fluorescence background obscures prominent Raman bands of mineral and matrix components of bone tissue. A 532-nm laser irradiation has been used efficiently to remove the fluorescence background from Raman spectra of cortical bone. Photochemical bleaching reduces over 80% of the fluorescence background after 2 h and is found to be nondestructive within 40 min. The use of electron multiplying couple charge detector (EMCCD) enables to acquire Raman spectra of bone tissues within 1-5 s range and to obtain Raman images less than in 10 min.

Animals↗
PubMed2004

Changes in chemical composition and collagen structure of dentine tissue after erbium laser irradiation.

Erbium laser radiation has a great affinity for the water molecule, which is present in quantity in biological hard tissues. The objective of this work is to identify chemical changes by infrared spectroscopy of irradiated dentine by an Er:YAG-2.94 microm laser. The irradiation was performed with fluences between 0.365 and 1.94 J/cm2. For the infrared analysis a Fourier transform infrared spectrometer was used. After the irradiation were observed: loss of water, alteration of the structure and composition of the collagen, and increase of the OH- radical. These alterations can be identified by a decrease in intensity of the water band between 2800-3800 cm(-1), OH- band at 3575 cm(-1) and bands ascribed to organic matrix between 2800-3400 cm(-1) and 1100-1400 cm(-1).

Absorption↗
PubMed2004

Structural and conformational properties of fluoroformic acid anhydride, FC(O)OC(O)F.

The conformational properties and geometric structures of fluoroformic acid anhydride, FC(O)OC(O)F, have been studied by vibrational spectroscopy, gas electron diffraction (GED), single-crystal X-ray diffraction, and quantum chemical calculations (HF, MP2, and B3LYP methods with 6-31G* and B3LYP/6-311+G* basis sets). Satellite bands in the IR matrix spectra, which increase in intensity when the matrix gas mixture is heated prior to deposition as a matrix, indicate the presence of two conformers at room temperature. According to the electron diffraction analysis, the prevailing conformer is of C(2) symmetry with both C=O bonds synperiplanar with respect to the opposite C-O bond ([sp, sp] conformer). The minor conformer [15(5)% from IR matrix and 6(11)% from GED] is predicted by quantum chemical calculations to possess an [sp, ac] structure. FC(O)OC(O)F crystallizes in the orthorhombic system in the space group P2(1)2(1)2(1) with a = 6.527(1) angstroms, b = 7.027(1) angstroms, and c = 16.191(1) angstroms and four formula units per unit cell. In the crystal, only the [sp, sp] conformer is present, and the structural parameters are very similar to those determined by GED.

Journal Article↗
PubMed2006

Optical properties of two-dimensional negative-phase-velocity-medium photonic crystals.

By an extended plane-wave-based transfer-matrix method, the photonic band structure and the corresponding transmission spectrum have been calculated for a two-dimensional photonic crystal composed of negative-phase-velocity-medium (NPVM) cylindrical rods. Dispersionless anticrossing bands in the two-dimensional NPVM periodic structure are generated by the couplings among surface polaritons localized in the NPVM rods. In part of the negative-phase-velocity frequency region, the photonic band structures of the NPVM photonic crystal are characterized by a topographical continuous dispersion relationship accompanied by many anticrossing bands. The effect of the filling fraction of the NPVM rods on the optical properties of photonic crystals has also been studied.

Journal Article↗