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| | 1. |
1993 Jul 1 |
Compilation of small ribosomal subunit RNA structures.
Neefs, Van de Peer, De Rijk, Chapelle, De Wachter
Nucleic Acids Res 1993 Jul 1;21(13):3025-3049.
Abstract
The database on small ribosomal subunit RNA structure contained 1804 nucleotide sequences on April 23, 1993. This number comprises 365 eukaryotic, 65 archaeal, 1260 bacterial, 30 plastidial, and 84 mitochondrial sequences. These are stored in the form of an alignment in order to facilitate the use of the database as input for comparative studies on higher-order structure and for reconstruction of phylogenetic trees. The elements of the postulated secondary structure for each molecule are indicated by special symbols. The database is available on-line directly from the authors by ftp and can also be obtained from the EMBL nucleotide sequence library by electronic mail, ftp, and on CD ROM disk.
[Pubmed: 8332525]
| | 2. |
2001 Sep 24 |
The efficacy of chemical agents in cleaning and disinfection programs
Penna, Mazzola, Silva Martins
BMC Infect Dis 2001 Sep 24;1:16. published online before print
Abstract
Due to the growing number of outbreaks of infection in hospital nurseries, it becomes essential to set up a sanitation program that indicates that the appropriate chemical agent was chosen for application in the most effective way.
[Pubmed: 11591223]
| | 3. |
1918 Jan |
Studies in the Nomenclature and Classification of the Bacteria
Buchanan
J Bacteriol 1918 Jan;3(1):27-61.
[Pubmed: 16558776]
| | 4. |
1965 Jun |
Mycoplasma Species of Man
Hayflick, Chanock
Bacteriol Rev 1965 Jun;29(2):185-221.
[Pubmed: 14304038]
| | 5. |
1952 Aug |
Nocardiosis
Cruz, Clancy
Am J Pathol 1952 Aug;28(4):607-627.
[Pubmed: 14943799]
| | 6. |
1922 Jul 14 |
Weekly Reports for JULY 14, 1922
Public Health Rep 1922 Jul 14;37(28):1675-1772.
[Pubmed: 19314834]
| | 7. |
1981 Oct |
Cimetidine and cytopenia.
Selker, Rosenbloom, Weinstein
West J Med 1981 Oct;135(4):330-336.
[Pubmed: 7342462]
| | 8. |
1949 Sep |
THE SYNTHESIS OF NUCLEIC ACIDS IN CULTURES OF ESCHERICHIA COLI, STRAINS B AND B/R
Morse, Carter
J Bacteriol 1949 Sep;58(3):317-326.
[Pubmed: 16561789]
| | 9. |
1929 Apr |
LEUKOPLAKIA OF THE KIDNEY PELVIS*
Kutzmann
Cal West Med 1929 Apr;30(4):244-249.
[Pubmed: 18741002]
| | 10. |
1923 Jan |
Bacteriophage Phenomena 1
Kuttner
J Bacteriol 1923 Jan;8(1):49-101.
[Pubmed: 16558985]
| | 11. |
1902 May |
Upon an extensive Outbreak of Food Intoxication and Infection of unique Origin , 12
Ohlmacher
J Med Res 1902 May;7(4):411-420.
[Pubmed: 19971475]
| | 12. |
2011 Jun 28 |
On the alleged origin of geminiviruses from extrachromosomal DNAs of phytoplasmas
Saccardo, Cettul, Palmano, Noris, Firrao
BMC Evol Biol 2011 Jun 28;11:185. published online before print
Abstract
Several phytoplasmas, wall-less phloem limited plant pathogenic bacteria, have been shown to contain extrachromosomal DNA (EcDNA) molecules encoding a replication associated protein (Rep) similar to that of geminiviruses, a major group of single stranded (ss) DNA plant viruses. On the basis of that observation and of structural similarities between the capsid proteins of geminiviruses and the Satellite tobacco necrosis virus, it has been recently proposed that geminiviruses evolved from phytoplasmal EcDNAs by acquiring a capsid protein coding gene from a co-invading plant RNA virus.
[Pubmed: 21711564]
| | 13. |
1974 Jun 1 |
THE ROLE OF MICROTUBULES IN THE MOVEMENT OF PIGMENT GRANULES IN TELEOST MELANOPHORES
Murphy, Tilney
J Cell Biol 1974 Jun 1;61(3):757-779.
Abstract
When microtubules in teleost melanophores are disrupted with antimitotic agents, colchicine, high hydrostatic pressure, low temperature, and vinblastine, the alignment and movement of the pigment granules in these cells disappear; during recovery, the return of alignment and movement corresponds in both time and space with the repolymerization of microtubules. Furthermore, analysis of nearest neighbor distances in untreated melanophores reveals that pigment granules are closely associated with microtubules. Other structures such as microfilaments, the endoplasmic reticulum, and the cytoplasmic matrix do not appear to be involved. Thus we conclude that microtubules determine the alignment and are essential for the selective movements of the pigment granules in these cells. Investigations of the mechanism of movement show that microtubules are required for both centrifugal and centripetal migrations and that they do not change in number or location during redistribution of pigment. Our results further indicate that microtubules in melanophores behave as semistable organelles as determined by investigation with colchicine and hydrostatic pressure. These observations and others rule out a push-pull mechanism based on the polymerization and depolymerization of microtubules or one which distinguishes two operationally different sets of microtubules. We propose instead that particles move by sliding along a fixed array of microtubules.
[Pubmed: 4836391]
| | 14. |
1960 Sep 1 |
ELECTRON MICROSCOPIC STUDIES OF MITOSIS IN AMEBAE
Roth, Obetz, Daniels
J Biophys Biochem Cytol 1960 Sep 1;8(1):207-220.
Abstract
Individual organisms of Amoeba proteus have been fixed in buffered osmium tetroxide in either 0.9 per cent NaCl or 0.01 per cent CaCl2, sectioned, and studied in the electron microscope in interphase and in several stages of mitosis. The helices typical of interphase nuclei do not coexist with condensed chromatin and thus either represent a DNA configuration unique to interphase or are not DNA at all. The membranes of the complex nuclear envelope are present in all stages observed but are discontinuous in metaphase. The inner, thick, honeycomb layer of the nuclear envelope disappears during prophase, reappearing after telophase when nuclear reconstruction is in progress. Nucleoli decrease in size and number during prophase and re-form during telophase in association with the chromatin network. In the early reconstruction nucleus, the nucleolar material forms into thin, sheet-like configurations which are closely associated with small amounts of chromatin and are closely applied to the inner, partially formed layer of the nuclear envelope. It is proposed that nucleolar material is implicated in the formation of the inner layer of the envelope and that there is a configuration of nucleolar material peculiar to this time. The plasmalemma is partially denuded of its fringe-like material during division.
[Pubmed: 13743845]
| | 15. |
2012 Jun 15 |
The genus Cladosporium
Bensch, Braun, Groenewald, Crous
Stud Mycol 2012 Jun 15;72(1):1-401.
Abstract
A monographic revision of the hyphomycete genus Cladosporium s. lat. (Cladosporiaceae, Capnodiales) is presented. It includes a detailed historic overview of Cladosporium and allied genera, with notes on their phylogeny, systematics and ecology. True species of Cladosporium s. str. (anamorphs of Davidiella), are characterised by having coronate conidiogenous loci and conidial hila, i.e., with a convex central dome surrounded by a raised periclinal rim. Recognised species are treated and illustrated with line drawings and photomicrographs (light as well as scanning electron microscopy). Species known from culture are described in vivo as well as in vitro on standardised media and under controlled conditions. Details on host range/substrates and the geographic distribution are given based on published accounts, and a re-examination of numerous herbarium specimens. Various keys are provided to support the identification of Cladosporium species in vivo and in vitro. Morphological datasets are supplemented by DNA barcodes (nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S nrDNA, as well as partial actin and translation elongation factor 1-α gene sequences) diagnostic for individual species. In total 993 names assigned to Cladosporium s. lat., including Heterosporium (854 in Cladosporium and 139 in Heterosporium), are treated, of which 169 are recognized in Cladosporium s. str. The other taxa are doubtful, insufficiently known or have been excluded from Cladosporium in its current circumscription and re-allocated to other genera by the authors of this monograph or previous authors.
[Pubmed: 22815589]
| | 16. |
2006 Dec |
[Murine typhus - rare cause of fever return from Egypt].
Rozsypal H, Aster V, Skokanová V
Klin. Mikrobiol. Infekc. Lek. 2006 Dec;12(6):244-6.
Abstract
Authors present a case report of 42-year male who spent 14 days in August of 2003 in Egyptian seaside summer town Hurghada and later he was admitted to the Infectious Disease Department Prague with the fever lasting 4 days. His symptoms were as follows: strong headache and dry cough. On the 7th and 8th day appeared transient maculopapular rash, laboratory test revealed a slightly elevated C reactive protein and elevation of amino transferases up to 5 times higher than range values, chest X-ray showed hypoventilation opacities on the lower lung fields, other findings were non-specifically changed or normal. The fever dropped after 15 days without any response to administered antibiotics-amoxicillin/clavulanate, clarithromycin a ofloxacin. Weil-Felix reaction with antigen Proteus OX19 (1 : 5120) was highly positive and positive antibodies IgG and IgM against Rickettsia typhi were positive. Later doxycycline was given, problems fully subsided, laboratory values were normalised up to six weeks from the beginning of the disease. Diagnosis was completed as murine typhus. The patient excluded arthropode bit. The authors considered the possibility of inhaled contaminated dust during his visit of the port. The above given case was firstly referred in the Czech Republic and still it is the only case.
[Pubmed: 17230380]
| | 17. |
1973 Dec |
[Comparative investigations on the activity of ciclacillin, ampicillin and carbenicillin (author's transl)].
Wewalka G, Rotter M, Gredler B, Aster L
Zentralbl Bakteriol Orig A. 1973 Dec;225(2):187-96.
[Pubmed: 4150051]
| | 18. |
1993 Jun 2 |
Cortical and cytoplasmic flow polarity in early embryonic cells of Caenorhabditis elegans
J Cell Biol 1993 Jun 2;121(6):1343-1355.
Abstract
We have examined the cortex of Caenorhabditis elegans eggs during pseudocleavage (PC), a period of the first cell cycle which is important for the generation of asymmetry at first cleavage (Strome, S. 1989. Int. Rev. Cytol. 114: 81-123). We have found that directed, actin dependent, cytoplasmic, and cortical flow occurs during this period coincident with a rearrangement of the cortical actin cytoskeleton (Strome, S. 1986. J. Cell Biol. 103: 2241-2252). The flow velocity (4-7 microns/min) is similar to previously determined particle movements driven by cortical actin flows in motile cells. We show that directed flows occur in one of the daughters of the first division that itself divides asymmetrically, but not in its sister that divides symmetrically. The cortical and cytoplasmic events of PC can be mimicked in other cells during cytokinesis by displacing the mitotic apparatus with the microtubule polymerization inhibitor nocodazole. In all cases, the polarity of the resulting cortical and cytoplasmic flows correlates with the position of the attenuated mitotic spindle formed. These cortical flows are also accompanied by a change in the distribution of the cortical actin network. The polarity of this redistribution is similarly correlated with the location of the attenuated spindle. These observations suggest a mechanism for generating polarized flows of cytoplasmic and cortical material during embryonic cleavages. We present a model for the events of PC and suggest how the poles of the mitotic spindle mediate the formation of the contractile ring during cytokinesis in C. elegans.
[Pubmed: 8509454]
| | 19. |
1983 Nov 1 |
Aggregates of acetylcholine receptors are associated with plaques of a basal lamina heparan sulfate proteoglycan on the surface of skeletal muscle fibers
J Cell Biol 1983 Nov 1;97(5):1396-1411.
Abstract
Hybridoma techniques have been used to generate monoclonal antibodies to an antigen concentrated in the basal lamina at the Xenopus laevis neuromuscular junction. The antibodies selectively precipitate a high molecular weight heparan sulfate proteoglycan from conditioned medium of muscle cultures grown in the presence of [35S]methionine or [35S]sulfate. Electron microscope autoradiography of adult X. laevis muscle fibers exposed to 125I-labeled antibody confirms that the antigen is localized within the basal lamina of skeletal muscle fibers and is concentrated at least fivefold within the specialized basal lamina at the neuromuscular junction. Fluorescence immunocytochemical experiments suggest that a similar proteoglycan is also present in other basement membranes, including those associated with blood vessels, myelinated axons, nerve sheath, and notochord. During development in culture, the surface of embryonic muscle cells displays a conspicuously non-uniform distribution of this basal lamina proteoglycan, consisting of large areas with a low antigen site-density and a variety of discrete plaques and fibrils. Clusters of acetylcholine receptors that form on muscle cells cultured without nerve are invariably associated with adjacent, congruent plaques containing basal lamina proteoglycan. This is also true for clusters of junctional receptors formed during synaptogenesis in vitro. This correlation indicates that the spatial organization of receptor and proteoglycan is coordinately regulated, and suggests that interactions between these two species may contribute to the localization of acetylcholine receptors at the neuromuscular junction.
[Pubmed: 6226669]
| | 20. |
1976 May 1 |
Pressure-induced depolymerization of spindle microtubules. III. Differential stability in HeLa cells
J Cell Biol 1976 May 1;69(2):443-454.
Abstract
Evidence from light microscopy (principally polarization microscopy) has demonstrated that hydrostatic pressure can reversibly inhibit mitosis by rapidly depolymerizing the spindle fiber microtubules. We have confirmed this finding in ultrastructural studies of mitotic HeLa cells incubated at 37 degrees C and pressurized at 680 atm (10,000 psi). Althouth there are many spindle microtubules in the cells at atmospheric pressure, electron micographs of cells pressurized for 10 min (and fixed while under pressure in a Landau-Thibodeau chamber) show few microtubules. Pressure has a differential effect on the various types of spindle microtubules. Astral and interpolar MTs appear to be completely depolymerized in pressurized cells, but occasional groups of kinetochore fiber microtubules are seen. Surprisingly, the length and density of microtubules of the stem bodies and midbody of telophase cells appear unchanged by pressurization. In cells fixed 10 min after pressure was released, microtubules were again abundant, the density often appearing to be higher than in control cells. Reorganization seems incomplete, however, since many of the microtubules are randomly oriented. Unexpectedly, kinetochores appeared diffuse and were difficult to identify in sections of pressurized cells. Even after 10 min of recovery at atmospheric pressure, their structure was less distinct than in unpressurized cells.
[Pubmed: 1262399]
| | 21. |
1968 Oct 1 |
THE FINE STRUCTURE OF ACANTHAMOEBA CASTELLANII
Bowers, Korn
J Cell Biol 1968 Oct 1;39(1):95-111.
Abstract
The fine structure of the trophozoite of Acanthamoeba castellanii (Neff strain) has been studied. Locomotor pseudopods, spikelike "acanthopodia," and microprojections from the cell surface are all formed by hyaline cytoplasm, which excludes formed elements of the cell and contains a fine fibrillar material. Golgi complex, smooth and rough forms of endoplasmic reticulum, digestive vacuoles, mitochondria, and the water-expulsion vesicle (contractile vacuole) are described. A canicular system opening into the water-expulsion vesicle contains tubules about 600 A in diameter that are lined with a filamentous material. The tubules are continuous with unlined vesicles or ampullae of larger diameter. Centrioles were not observed, but cytoplasmic microtubules radiate from a dense material similar to centriolar satellites and are frequently centered in the Golgi complex. Cytoplasmic reserve materials include both lipid and glycogen, each of which amounts to about 10% of the dry weight.
[Pubmed: 5678452]
| | 22. |
1965 Apr 1 |
SOME OBSERVATIONS CONCERNING METAKINESIS IN SEA URCHIN EGGS
Harris
J Cell Biol 1965 Apr 1;25(1):73-77.
[Pubmed: 14342831]
| | 23. |
1965 Mar 1 |
STRUCTURE OF THE MITOTIC SPINDLE IN L STRAIN FIBROBLASTS
Krishan, Buck
J Cell Biol 1965 Mar 1;24(3):433-444.
Abstract
The mitotic spindle of L strain fibroblasts, fixed with glutaraldehyde followed by osmium tetroxide, contains many 150- to 180-A tubules. They appear first in the cytoplasm. They extend from the centrospheres to the kinetochores, and from one centrosphere to the other. Only occasionally can points of continuity between the spindle tubules and the tubules of the centrioles be observed. The chromosomal insertion is by a means of a thin dense plate of the kinetochore. The total number of continuous spindle tubules is between 500 and 600. Occasionally, tubules appear paired. At anaphase, short lengths of individual spindle tubules possess a coating of a substance of high density midway between the poles. These parts of the spindle tubules aggregate to form irregular groups, comprising the stem-body, and, by becoming aligned into a plate, they form the mid-body.
[Pubmed: 14326124]
| | 24. |
1963 Aug 1 |
CYTOPLASMIC MICROTUBULES
Slautterback
J Cell Biol 1963 Aug 1;18(2):367-388.
Abstract
Small cytoplasmic tubules are present in the interstitial cells and cnidoblasts of hydra. They are referred to here as "microtubules." These tubular elements have an outside diameter of 180 A and an inside diameter of 80 A. By difference, the membranous wall is estimated to be 50 A thick. The maximum length of the microtubules cannot be determined from thin sections but is known to exceed 1.5 µ. In the interstitial cells the microtubules are found in the intercellular bridges, free in the cytoplasm and in association with the centrioles. In the cnidoblast they form a framework around the developing nematocyst and in late stages are related to the cnidocil forming a tight skein in the basal part of the cell. Especially in this cell, confluence of microtubules with small spherical vesicles of the Golgi complex has been observed. It is proposed that these tubules function in the transport of water, ions, or small molecules.
[Pubmed: 14079495]
| | 25. |
1962 Sep 1 |
SOME STRUCTURAL AND FUNCTIONAL ASPECTS OF THE MITOTIC APPARATUS IN SEA URCHIN EMBRYOS
Harris
J Cell Biol 1962 Sep 1;14(3):475-487.
Abstract
The mitotic figures in dividing cells of sea urchin embryos, from first division to the onset of cilia formation, were studied with regard to the filament system and its relation to kinetochores, chromosomes, and poles, as well as to fixation conditions which would best preserve these structures. With regard to fixation, variations in the salt concentration and pH of the fixative indicated that an extraction effect on the chromosomes noted in earlier work was probably due to a combination of neutral pH and salt concentration equivalent to sea water. The presence of the 15 mµ filaments depended on the presence of either of two stabilizing conditions: pH 6.1 or presence of the salts of sea water, presumably the divalent cations of Ca and Mg. Kinetochores and centrioles were unaffected by the fixative variations. The 15 mµ filaments, reported earlier in the central spindle, are also found in great numbers in the asters of early cleavage divisions. However, with successive divisions and reduction in cell size, the aster disappears at about the 32 to 64 cell stage, and the 15 mµ filaments are entirely associated with the central spindle. This disappearance of the aster suggests that it may be, in fact, merely a specialization of large cells for cytokinesis.
[Pubmed: 13952946]
| | 26. |
1961 Nov 1 |
ELECTRON MICROSCOPE STUDY OF MITOSIS IN SEA URCHIN BLASTOMERES
Harris
J Biophys Biochem Cytol 1961 Nov 1;11(2):419-431.
Abstract
The fine structure of cells at different stages of the mitotic cycle was studied in the blastomeres of 6-hour-old embryos of the sea urchin Strongylocentrotus purpuratus. The material was fixed in 1 per cent osmium tetroxide in sea water, buffered with veronal-acetate to pH 7.5, embedded in Araldite, and sectioned with glass knives. The aster, as it forms around the centriole, has the appearance of the endoplastic reticulum, with elements oriented radially from the centrosphere to the periphery of the cell. Anaphase structures described include the kinetochores, with bundles of fine filaments extending toward the centrioles, as well as continuous filaments passing between the chromosomes. Two cylindrical centrioles composed of parallel rods are present in each of the anaphase asters. At late anaphase, elements of the endoplasmic reticulum condense on the surface of the chromosomes to form a double membrane which already at this stage possesses pores or annuli. At telophase bundles of continuous filaments can be seen in the interzonal region. These filaments, as well as those associated with the chromosomes, have a diameter of approximately 15 mµ, and appear physically different from the astral structure.
[Pubmed: 13904865]
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