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At least 469 records · Page 26Linked to original sources
PubMed1985

Proteins closely similar to flagellar tektins are detected in cilia but not in cytoplasmic microtubules.

Affinity-purified antibodies against Strongylocentrotus purpuratus sperm flagellar tektin polypeptides have been tested for cross-reactivity with microtubules isolated from various sources, using indirect immunofluorescent staining and antibody binding to nitrocellulose replicas of SDS polyacrylamide gels. The antitektins reacted with sperm tail axonemes from four genera of sea urchins and with cilia from sea urchin embryos. Antibody binding was observed only if the specimens were prefixed by methods that would not preserve them well at an ultrastructural level. However, even after such fixation regimes, no antibody binding was detected to cytoplasmic microtubule arrays in the same embryos, to mitotic spindles isolated from sea urchin eggs or to gill cilia from a mollusc. We conclude that, if tektins are present in sea urchin egg cytoplasmic microtubules, they are sufficiently different from the sperm tektins to have no common strongly antigenic determinants.

Animals↗
PubMed1986

Isolation of cilia from porcine tracheal epithelium and extraction of dynein arms.

Milligram amounts of mammalian ciliary axonemes were isolated from porcine tracheas. These were reactivated upon addition of ATP, indicating intact functional capability with a mean beat frequency at 37 degrees C of 8.2 Hz. Electron microscopy showed typical ultrastructure of the isolated demembranated axonemes. Electrophoresis into polyacrylamide gradient gels containing sodium dodecyl sulfate revealed reproducible protein profiles from ten different tracheal preparations. Four major protein bands were observed in the 300-330 K molecular weight region, as well as tubulin at 51-54K. Extraction of the isolated tracheal axonemes with 0.6M KCl removed the outer dynein arms seen in electron microscopic cross-section of axonemes, preferentially solubilized two of the high molecular weight proteins at 320 and 330 K, and resulted in a three- to four-fold increase in ATPase specific activity. Sedimentation of the dialyzed salt extract on a 5-30% sucrose density gradient and subsequent fractionation yielded two peaks of ATPase activity. The faster migrating, 19S major ATPase peak correlated with the 320 and 330 K proteins, and two other proteins at 81 and 67 K. The slower sedimenting, 12S minor ATPase peak corresponded to a 308 K protein and two smaller proteins at 33 and 48 K. Thus, the outer dynein arm of tracheal cilia appeared to be associated with at least two high molecular weight proteins. These results demonstrate that adequate quantities of functionally intact axonemes can be reproducibly isolated from porcine tracheas, allowing further fractionation and analysis of mammalian cilia.

Adenosine Triphosphatases↗
PubMed1992

Reactivation of newt lung cilia: evidence for a possible temperature- and MgATP-induced activation mechanism.

Optimal conditions have been developed for the isolation and reactivation of highly coupled, demembranated ciliary axonemes from newt lungs [Hard, Cypher, and Schabtach, 1988, Cell Motil. Cytoskeleton 10:271-284]. In the present study, the motility of these cilia was further characterized by examining the effects of nucleotides, divalent cations, and temperature on beat frequency. When exposed to a reactivating solution containing Mg2+ and ATP, nearly 100% of the axonemes were motile and beat at frequencies of 0-50 Hz, depending on [MgATP] and temperature. Divalent cations were required for movement, with Mg2+ 2-3 times more effective than Ca2+. There was no absolute requirement for Ca2+ for motility. The beat frequencies obtained with fixed ATP and varying Mg2+ concentrations indicate that MgATP serves as the actual substrate. The effects of MgATP on beat frequency depended on the degree of mechanochemical coupling and temperature. When highly coupled preparations were reactivated at 21 degrees C, double reciprocal plots of beat frequency vs. [MgATP] were biphasic with extrapolated Fmax values of 22 and 44.8 Hz. However, when reactivated at 10 degrees C and 30 degrees C, linear plots were generated with Fmax values of 18.3 and 48.9 Hz, respectively. The beat frequencies of cultured cells and reactivated axonemes also varied biphasically with temperature. Our data suggest that newt lung respiratory cilia possess an intra-axonemal activation mechanism involving a temperature- and MgATP-induced transition between two distinct states whose maximum beat frequencies differ by 200-300%.

Adenosine Triphosphate↗
PubMed1993

Immunological comparison of 22S, 19S, and 12S dyneins from Paramecium cilia.

Three forms of dynein (22S, 19S, and 12S) were purified from Paramecium cilia. Two classes of monoclonal antibodies against purified 22S dynein were generated. One class reacted on immunoblots with the heavy chains of 22S, 19S, and 12S dyneins; the second class reacted with an 88 kD intermediate chain of 22S dynein. Polyclonal antiserum to the heavy chains of 22S dynein reacted with the alpha-heavy chain of 22S and 19S dyneins. A previously described antiserum raised against 22S dynein [Travis et al.: Biochim. Biophys. Acta 966:73-83, 1988] recognized the gamma-heavy chain of 22S dynein which was also present in 19S and 12S dyneins, along with the 88 and 76 kD intermediate chains of 22S dynein. This antiserum was also able to immunoprecipitate dynein from crude extracts of cilia. Electron microscopy revealed that the 22S dynein consisted mainly of two-headed particles with some three-headed particles present. The 12S dynein was mainly one-headed particles. The 19S dynein was a mixture of three-, two-, and one-headed particles. The immunological and electron microscopic studies showed that 19S dynein arises from 22S dynein, and that 12S dynein is heterogeneous, composed of the gamma-heavy chain of 22S dynein and a unique dynein ATPase. The polyclonal antibodies were also used to detect cross-reactive proteins in other organisms. Both the anti-heavy chain and the anti-22S dynein sera reacted strongly with 22S outer arm dynein of Tetrahymena, but not with the 14S dynein of this organism.

Animals↗
PubMed1995

Detached single cilia: another potential pseudomicrobe seen in bronchoalveolar lavage specimens.

High magnification examination of Romanovsky-stained bronchoalveolar lavage (BAL) material may be needed, if one is to confidently exclude small organisms such as toxoplasmosis, histoplasmosis, and the negative images of mycobacteria. Pseudomicrobes have been described, and detailed criteria must be carefully applied, if incorrect diagnoses are to be avoided. We recently noted numerous free-lying, uniform, eosinophilic, straight or slightly curved bacilliform structures in such a specimen. These were seen on Diff-Quik-stained material, but were extremely pale on Papanicolaou-stained slides. Comparison with the cilia of contaminating bronchial cells showed these pseudomicrobes to have similar length, diameter, and tinctorial properties. Electron microscopy of the sedimented cell pellet showed isolated, detached single cilia (DSC) far removed from any bronchial cells. Twenty BAL's from 13 males and seven females (median age = 48.5) undergoing infection surveillance were then retrospectively reviewed. DSC were present in 16 specimens (80%), but were rare in three of these. Although present in cases with prominent bronchial cell contamination (n = 6 cases), DSC were also encountered when ciliated cells were rare (n = 13), or absent (n = 1). Familiarity with these distinctive structures should make it unlikely that they will be mistaken for infectious organisms.

Adolescent↗
PubMed1977

Effect of calcium on the pellet height response of Tetrahymena cilia.

The pellet height response (a measure of the increase in height of the pellet of cilia obtained by brief centrifugation in the presence of ATP as compared to the absence of ATP) of Tetrahymena cilia prepared by deciliation in the presence of Ca2+ is sensitive to the concentration of free Ca2+ during the pellet height assay. The magnitude of the increase in pellet height and the sharpness of the pellet boundary both increase markedly with increasing [Ca2+]. The half-maximal effect is attained at a free [Ca2+] of about 1.5 x 10(-7) M. The pellet height assay thus measures a Ca2+-sensitive component of the ciliary motile system. The possibility that this is the Ca2+-sensitive orientation system is discussed.

Adenosine Triphosphate↗
PubMed1992

Cilia in children with recurrent upper respiratory tract infections: ultrastructural observations.

We investigated the ultrastructure of nasal cilia in 27 children suffering from recurrent infections of the upper respiratory tract, during and after the onset of an acute respiratory infection, and after a convalescent period of 12 weeks. Our results demonstrated that in seven subjects after resolution of infection, the morphology of a large proportion of the cilia (32%) was not back to normal. These findings suggest a long-term residual effect of infection, or the inability to reestablish normal ciliary structure during the convalescent period in some subjects with recurrent upper respiratory tract infection.

Acute Disease↗
PubMed1996

Expression of primary cilia in mammalian cells.

Mammalian cells in vivo frequently express primary cilia. Although some fully differentiated cell types rarely, if ever, express them, most do, indicating that they are regular cell organelles. Their expression can also be explored in vitro, where conditions--physical and chemical, intrinsic and extrinsic--permit experimental approaches which give far greater control than in vivo. This 'state of the art' paper covers briefly the general biology of primary cilia, highlights the current situation with regard to our understanding of their relevance and importance in cell biology from various facets of our recent research, much of it in collaboration with other laboratories world-wide, and outline future work aimed at answering some basic and applied questions about them, within a context of an increasing awareness that signalling between cells is of the utmost importance in understanding proliferation control and its value in cancer research, the major remit of this unit.

Animals↗
PubMed1997

Confocal analysis of primary cilia structure and colocalization with the Golgi apparatus in chondrocytes and aortic smooth muscle cells.

Detyrosinated and acetylated alpha-tubulins represent a stable pool of tubulin typically associated with microtubules of the centrosome and primary cilium of eukaryotic cells. Although primary cilium-centrosome and centrosome-Golgi relationships have been identified independently, the precise structural relationship between the primary cilium and Golgi has yet to be specifically defined. Confocal immunohistochemistry was used to localize detyrosinated (ID5) and acetylated (6-11B-1) tubulin antibodies in primary cilia of chondrocytes and smooth muscle cells, and to demonstrate their relationship to the Golgi complex identified by complementary lectin staining with wheat germ agglutinin. The results demonstrate the distribution and inherent structural variation of primary cilia tubulins, and the anatomical interrelationship between the primary cilium, the Golgi apparatus and the nucleus. We suggest that these interrelationships may form part of a functional feedback mechanism which could facilitate the directed secretion of newly synthesized connective tissue macromolecules.

Acetylation↗
PubMed1995

Larval spicules, cilia, and symmetry as remnants of indirect development in the direct developing sea urchin Heliocidaris erythrogramma.

Nonfeeding larvae of the echinoid Heliocidaris erythrogramma were raised in culture and examined for expression of a larval skeleton and for the arrangement of the ciliated band. Opaque larvae were fixed, cleared, and examined under polarized light for evidence of calcification. By 35 hr after fertilization (at 22 degrees C), a pair of triradiate spicules was present at the posterior end of the larvae. Each member of this pair formed a fenestrated spicule as it grew laterally. This pair and another pair which formed subsequently, were arranged across a plane of bilateral symmetry orthagonal to the juvenile oral aboral axis. These paired larval spicules can be identified as reduced expressions of postoral and posterodorsal rods found in plutei, and their expression indicates that the juvenile rudiment of H. erythrogramma forms on the left side and that larval body axes are conserved in this modified larva. By 44 hr the ciliated band formed as an incomplete transverse loop of three segments at the posterior end and on the dorsal surface of the ovoid larva. Cilia in these segments grew to lengths of 45-50 microns, longer than other swimming and feeding cilia reported for echinoderm larvae. Band segments are interpreted as expressions of epaulettes (specialized swimming bands) rather than the feeding ciliated band of the pluteus. The ciliated band segments and the larval spicules are both bilaterally symmetrical with respect to the same plane and indicate conserved larval bilateral symmetry despite the major asymmetry of the fates of cells on either side of this plane in their contribution to juvenile development.

Animals↗
PubMed1994

Polymorphonuclear leukocyte-generated oxygen metabolites decrease beat frequency of human respiratory cilia.

We investigated the effect of polymorphonuclear leukocyte (PMN)-generated oxygen metabolites on the ciliary beat frequency. PMNs were incubated with human respiratory cilia obtained by nasal brushing. The oxidative metabolism was stimulated by opsonized zymosan, and ciliary beat frequency was evaluated before and after activation of PMNs. Ciliary beat frequency was studied using video microscopy. Our results demonstrate a significant decrease in ciliary beat frequency after activation of PMNs. This effect was reduced by catalase. These data suggest that the PMN-generated oxygen metabolites, particularly H2O2, decrease beat frequency of human respiratory cilia.

Ascorbic Acid↗
PubMed1991

Short nasal respiratory cilia and impaired mucociliary function.

A 48-year-old man was examined because of anosmia. He was otherwise healthy except for mild arterial hypertension. He had stopped smoking 20 years ago. Previously he had been exposed to sulfuric acid gases for 3 years in his work. Clinical examination revealed no findings to explain his anosmia. The patient was fertile, indicating normal sperm/cilia motility. Nasal mucociliary function was examined by radioactive tracer and found to be markedly and constantly impaired. Ciliary ultrastructure in cross-sections was normal. However, in longitudinal sections the length of the cilia varied from 0.6 microns to 3.9 microns. The mean length of the cilia from the cell membrane to the tip was 2.5 +/- 0.9 microns, in contrast to normal ciliary length of 5-7 microns. These findings represent a new structural defect among the various known ciliary abnormalities.

Cilia↗
PubMed1990

Ciliary orientation in the "immotile cilia" syndrome.

Ciliary orientation was studied in 43 patients with the "immotile cilia" syndrome. Twenty-four of these patients had total situs inversus. One mucosal specimen was taken from uterine cervical epithelium, 2 were from bronchial mucosa and 40 from nasal mucosa. The orientation of the cilia was measured from micrographs using a semiautomatic image analyzer (IBAS I). The results from patients were compared with those of 10 control subjects. The mean standard deviation and its standard deviation of the angles of ciliary orientation was 39.7 degrees +/- 9.2 degrees in 43 patients and 27.4 degrees +/- 4.3 degrees in the control group. The difference between the groups is highly significant statistically (P less than or equal to 0.001). However, there were no statistically significant differences in the standard deviations of ciliary orientation between the fields sectioned near the cell membrane or near the ciliary tip. We were also unable to find any significant differences in the standard deviations of the ciliary angles in the specimens taken from brush biopsies and excisional biopsies. There were also no statistically significant differences between the standard deviations of the ciliary angles for the groups with or without situs inversus. If 35 degrees is considered to be the limit value for the mean standard deviation between normal and pathological specimens in our total material, this would give a specificity of 0.90 and a sensitivity of 0.72.

Biopsy↗
PubMed1978

The structure of the tips of mammalian respiratory cilia.

The ciliary crown and the relationship of the ciliary crown to the underlying axoneme were studied by electron microscopy in cilia from hamster and rat trachea and bronchioles, and rabbit trachea. The ciliary crown is a cluster of 4 to 6 fibrils 35 nm long protruding beyond the plasma membrane at the tips of the cilia. The fibrils are well preserved after tannic acid-glutaraldehyde-osmium tetroxide fixation and have high contrast with a periodic density of 4.5 nm. They stain relatively weakly with phosphotungstic acid. The surface of the fibrils stains with ruthenium red. The microtubules of the axonemem end in a plate of electron dense amorphous material. A five layered disc occupies the space between the membrane and the amorphous plate at the tip of the axoneme. The plasma membrane can be dissolved with the detergent triton X-100 without loss of the ciliary crown. This indicates that the ciliary crown is composed of transmembranous filaments which are bound to the disc at the tip of the axoneme.

Animals↗
PubMed1977

Further observations of transport within paddle cilia.

Rhabdopleura has densely ciliated tentacles and cephalic shield. These cilia are of two sorts, ordinary cilia and those bearing paddle-like swellings. These swellings, about 1 micron across, are in the ciliary membrane. The axoneme bundle within the cilium remains intact, keeping the usual spatial arrangements, except that in the swelling its overall diameter is reduced. It is suggested that the mechanism for moving the paddle-like swellings along the length of the cilium is the releasing and reattaching of the side filaments from the axoneme to the ciliary membrane.

Animals↗
PubMed1980

Rudimentary cilia in muscle cells of annelids and echinoderms.

Rudimentary cilia have been observed in muscle cells lining the tube feet of Ophioderma brevispinum (Ophiuroidea) and in muscle cells of the body wall and parapodial glands of Owena fusiformis (Polychaeta). A diplosomal basal body is associated with each cilium. Striated rootlets are absent. This is the first report on rudimentary cilia in muscle cells of an echinoderm and an annelid.

Animals↗
PubMed1979

Kartagener's syndrome and the syndrome of immotile cilia.

Kartagener's syndrome (KS) is a hereditary disease with typical symptoms of situs inversus, bronchiectasis, and chronic infections of the nasal mucosa. Autosomal recessive inheritance cannot be doubted on account of repeated observations of affected sibs and parental cansanguinity. The bronchopulmonary symptoms in sibs, however, cannot be explained by this mode of inheritance. Recent clinical findings and electron microscope investigations suggest that KS is a special form of manifestation within the immotile cilia syndrome. This disease combines the typical bronchial and nasal symptoms of KS with sterility in the male due to immotile sperm tails and, as a facultative symptom, situs inversus. Thus, sibs with bronchiectasis but without situs inversus are also classified under this syndrome. The symptoms mentioned are caused by an abnormal morphology of bronchial cilia and sperm tails, which can be demonstrated by electron microscopy. The dynein arms normally attached to the nine microtubular doublets and providing a normal ciliary movement are lacking. It is assumed that during early embryonic life ciliary beats in the growing embryo determine the type of laterality. When ciliary movements are absent laterality may develop fortuitously, thus effecting a situs inversus in about half the affected cases. The numerical evaluation of pedigrees from the literature supports this assumption.

Cilia↗
PubMed1989

The preservation and regeneration of cilia on human nasal epithelial cells cultured in vitro.

Dissociated human nasal epithelial cells from nasal polyps were cultured in Ham's F12-DME 1/1 supplemented with NU-serum 10%, choleratoxin (10 ng/ml), retinoic acid (10(-7) M) and antibiotics. In monolayer cultures, the epithelial cells grew to confluency on collagen gels, became squamous, and lost their cilia within 2-6 weeks. In suspension cultures, epithelial cell sheaths formed stable vesicles and aggregates. These maintained a respiratory-type morphology and normal ciliary activity for over 6 months. When deciliated, squamous cells from monolayer cultures were brought in suspension, a respiratory-type morphology with cilia reappeared. This in vitro ciliogenesis resulted in normal and coordinated ciliary activity observed for more than 5 months.

Cells, Cultured↗