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PubMed1985

Three-dimensional analysis of dendritic spines. II. Spine apparatus and other cytoplasmic components.

A total of 342 dendritic spines (193 from the visual and 149 from the cerebellar cortex of the mouse) were analyzed in serial and several hundred of thousands of them in single sections, with respect to the presence and organization of the spine apparatus and other cytoplasmic components. The continuity of the spine apparatus with the smooth endoplasmic reticulum of the dendritic trunk was shown in three-dimensional reconstructions. The dense material of the spine apparatus was divided into "inner dense plate" and "outer dense plate". The close relationship between the outer dense plate and the postsynaptic density suggests that the spine apparatus functions as a postsynaptic protein synthesizing centre. The material from the outer dense plate could be used for a dynamic extension of the synaptic active zone. An extraspinous spine apparatus of the axon initial segment was partially reconstructed. Polyribosomes were found in all large spines of the visual cortex but were not so frequent in small spines and in Purkinje cell dendritic spines. Microfilamentous network and intermediate filaments occurred in the spines. The smooth endoplasmic reticulum of Purkinje cell dendritic spines was reconstructed. No spine apparatus and dense material were present in these spines.

Animals↗
PubMed1982

The control of anthozoan cilia by the basal apparatus.

The ciliary basal apparatus in the pharynx of the sea anemone, Calliactis parasitica (Couch), is composed of two centrioles, a single striated rootlet at least 20 microns long, and a basal foot, to the tip of which is attached a bundle of microtubules leading to the rootlet. When the basal apparatus is sectioned in the plane of the ciliary power-stroke, the distal centriole, with which the cilium base is continuous, is rarely found to be erect. The orientation of the distal centriole is determined by bending in the basal apparatus. Bending occurs only in the plane of the ciliary power-stroke towards the side from which the basal foot projects, and it is closely correlated with membrane buckling in the belt desmosome region of the cell apex. Associated with the belt desmosome, but not directly with the basal apparatus, are bundles of filaments. These filaments are of two size classes, 5-6 and 10 nm in diameter. A model is presented in which the 5-6 nm filaments form the basis of a contractile system which mediates membrane buckling in the region of the belt desmosome. This action effectively shortens the cell apex and thus forces the apparatus to bend. The precise reorientation of the distal centriole is a result of the mechanical properties of the basal apparatus.

Animals↗
PubMed1982

Venom apparatus of braconid wasps: comparative ultrastructure of reservoirs and gland filaments.

Two types of venom apparatus present in female braconid wasp were examined in nine species and compared ultrastructurally. The reservoir of type 1 venom apparatus has a relatively thick muscular sheath which is innervated, while the longitudinal and circular muscles of the type 2 reservoir consist of scattered fibers which are not innervated. The intima of the reservoir of type 1 venom apparatus is unevenly thickened. In contrast, the reservoir of type 2 venom apparatus has a relatively thinner and more uniform intima. The gland filaments of both types of venom apparatus are ultrastructurally similar. Distinct particles found in the venom apparatus of two of the nine species are described.

Animals↗
PubMed1980

Isolation of mitotic apparatus containing vesicles with calcium sequestration activity.

We present the first report of isolate mitotic apparatus with vesicular calcium sequestration. Phase-contrast, differential interference contrast and polarized light microscopy as well as transmission and scanning electron microscopic examinations revealed structures comparable to mitotic apparatus in vivo. Numerous membrane-bound vesicles which retained their osmotic activity were present throughout. Microtubules, yolk, ribosomes and condensed chromatin were also present. The protein composition of mitotic apparatus was not dramatically altered by treatment with 0.5% Triton X-100, even though vesicles were destroyed and yolk was extracted. Calcium sequestration was demonstrated with ATP-dependent accumulation of 45Ca by mitotic apparatus whose vesicles were left intact. Compared with controls for which no nucleotide was added, accumulation by mitotic apparatus with intact vesicles was enhanced to 184% when it was present. When ATP was supplemented with the divalent ionophore A23187, the calcium retention level was comparable to that of the control to which no nucleotide was added. Finally, the calcium accumulation by mitotic apparatus treated with either of the nonhydrolyzable ATP analogs AMPPCP or AMPPNP resulted in calcium retention levels similar to those of controls. The solubilization of vesicles with Triton X-100 abolished calcium accumulation in the presence or absence of any of the above additives. Resolution of vesicles on sucrose step gradients after 45Ca-oxalate loading with ATP or AMPPCP indicates that a specific vesicular fraction sequesters 45Ca.

Animals↗
PubMed2002

The development and evaluation of a three-dimensional ultrasound-guided breast biopsy apparatus.

We have designed a prototype three-dimensional ultrasound guidance (3D USB) apparatus to improve the breast biopsy procedure. Features from stereotactic mammography and free-hand US-guided biopsy have been combined with 3D US imaging. This breast biopsy apparatus accurately guides a needle into position for the sampling of target tissue. We have evaluated this apparatus in three stages. First, by testing the placement accuracy of a needle in a tissue mimicking phantom. Second, with tissue mimicking phantoms that had embedded lesions for biopsy. Finally, by comparison to free-hand US-guided biopsy, using chicken breast phantoms. The first two stages of evaluation quantified the mechanical biases in the 3D USB apparatus. Compensating for these, a 96% success rate in targeting 3.2 mm "lesions" in chicken breast phantoms was achieved when using the 3D USB apparatus. The expert radiologists performing biopsies with free-hand US guidance achieved a 94.5% success rate. This has proven an equivalence between our apparatus, operated by non-experts, and free-hand biopsy performed by expert radiologists, for 3.2 mm lesions in vitro, with a 95% confidence.

Animals↗
PubMed2001

Comparison of the hanson microette and the Van Kel apparatus for in vitro release testing of topical semisolid formulations.

PURPOSE: The major goal of this study was to compare the relative utility of the Hanson Microette and the Van Kel apparatus, two fully automated devices, as in vitro release tests (IVRT) for semisolids. We attempted to develop methodology that can be used to discriminate formulation changes, and to evaluate the precision, reproducibility and technical complexity of each test apparatus. METHODS: We chose the sunscreen Eusolex 232 (2-Phenylbenzimidazole-5-sulfonic acid) as a model compound, which was incorporated into an emulsion formulation prepared in our laboratory. Test conditions for the two IVRT were made as nearly identical as possible, in order to obtain an accurate comparison. RESULTS: The formulations were tested and found to be physically stable throughout the entire study. Diffusion coefficients were apparatus-dependent but were independent of the drug concentration in the formulations. The IVRT data were plotted as amount released (microg/cm2) vs. square root of time (s(0.5)) and a linear relationship was obtained in each case. Both methods produced similar results and were able to detect changes in drug loading in the formulations. CONCLUSIONS: The linear relationship between the amount released and the square root of time indicates a diffusion-controlled release of drug. Both apparatuses proved to be suitable as tests for formulation " sameness" according to the FDA's SUPAC-SS guidelines, during level 3 changes. However, each apparatus produced a different release profile for the drug. The choice of apparatus will depend upon a number of considerations.

Administration, Topical↗
PubMed2003

Synaptopodin-deficient mice lack a spine apparatus and show deficits in synaptic plasticity.

The spine apparatus is a cellular organelle that is present in many dendritic spines of excitatory neurons in the mammalian forebrain. Despite its discovery >40 years ago, the function of the spine apparatus is still unknown although calcium buffering functions as well as roles in synaptic plasticity have been proposed. We have recently shown that the 100-kDa protein synaptopodin is associated with the spine apparatus. Here, we now report that mice homozygous for a targeted deletion of the synaptopodin gene completely lack spine apparatuses. Interestingly, this absence of the spine apparatus is accompanied by a reduction in hippocampal long-term potentiation (LTP) in the CA1 region of the hippocampus and by an impairment of spatial learning in the radial arm maze test. This genetic analysis points to a role of the spine apparatus in synaptic plasticity.

Animals↗
PubMed2004

The impact of high CO2 concentrations on the structure and function of the photosynthetic apparatus and the role of polyamines.

Here we examined the influence of high CO2 concentrations on the structure and functioning of the photosynthetic apparatus in the unicellular green alga Scenedesmus obliquus. Presented in this work are: chlorophyll (Chl) a fluorescence induction kinetics, measurements of photosynthetic and respiration rates, estimation of Chl a/Chl b ratios, isolation and quantitative assessment of the photosynthetic subcomplexes, quantitative analyses of thylakoid bound polyamines, and experiments with exogenously supplied polyamines with cultures grown in low- and high-CO2 concentrations. Together, they indicated that high-CO2 concentrations affect polyamines and, more specifically, increase the thylakoid bound putrescine (PUT) level that leads to an increase of the active reaction center density combined with a decrease in the LHCII-size and the ratio of LHCII-oligomeres/LHCII-monomeres. This reorganization of the photosynthetic apparatus leads to enhanced photosynthetic rates, which in combination with the high-CO2 concentrations, leads to an immense increase of biomass (800%). Further incubation for longer time periods under the same conditions produces, due to an increase in cell density, a self-shading effect and photoadaptation of the photosynthetic apparatus to low light conditions and therefore also results in reduction of the high-CO2 effect. The photoadaptation of the photosynthetic apparatus to high-light conditions (Kotzabasis et al. 1999) and the acclimation to high-CO2 concentrations (present work) lead to the same changes in the structure and function of the photosynthetic apparatus. These changes could be induced or inhibited through the manipulation of intracellular polyamines, especially through the putrescine/spermine ratio. The possibility that polyamines influence the photoadaptation of the photosynthetic apparatus and its acclimation to high-CO2 concentrations through a common mechanism is discussed.

Carbon Dioxide↗
PubMed1979

Tubulin and calmodulin. Effects of microtubule and microfilament inhibitors on localization in the mitotic apparatus.

Indirect immunofluorescence was used to determine the distribution of calmodulin in the mitotic apparatus of rat kangaroo PtK2 and Chinese hamster ovary (CHO) cells. The distribution of calmodulin in PtK2 cells was compared to the distribution of tubulin, also as revealed by indirect immunofluorescence. During mitosis, calmodulin was found to be a dynamic component of the mitotic apparatus. Calmodulin first appeared in association with the forming mitotic apparatus during midprophase. In metaphase and anaphase, calmodulin was found between the spindle poles and the chromosomes. While tubulin was found in the interzonal region throughout anaphase, calmodulin appeared in the interzone region only at late anaphase. The interzonal calmodulin of late anaphase condensed during telophase into two small regions, one on each side of the midbody. Calmodulin was not detected in the cleavage furrow. In view of the differences in the localization of calmodulin, tubulin, and actin in the mitotic apparatus, experiments were designed to determine the effects of various antimitotic drugs on calmodulin localization. Cytochalasin B, an inhibitor of actin microfilaments, had no apparent effect on calmodulin or tubulin localization in the mitotic apparatus of CHO cells. Microtubule inhibitors, such as colcemid and N2O, altered the appearance of tubulin- and calmodulin-specific fluorescence in mitotic CHO cells. Cold temperature (0 degrees C) altered tubulin-specific fluorescence of metaphase PtK2 cells but did not alter calmodulin-specific fluorescence. From these studies, it is concluded that calmodulin is more closely associated with the kinetichore-to-pole microtubules than other components of the mitotic apparatus.

Animals↗
PubMed1999

Long-lasting contamination of a vitrectomy apparatus with Serratia marcescens.

OBJECTIVE: To investigate the contamination of a vitrectomy apparatus with Serratia marcescens. DESIGN: Descriptive microbiological and molecular environmental study. SETTING: An 1,800-bed university hospital. RESULTS: S. marcescens was found inside the vitrectomy apparatus at the pressure transducer. Molecular typing by randomly amplified polymorphic DNA-automated laser fluorescence analysis and pulsed-field gel electrophoresis identified a single pattern for all strains isolated from the apparatus. Surprisingly, the contaminating strain was identical to two strains of S. marcescens isolated nearly 2 years earlier from two patients who were involved in a small outbreak of acute postoperative endophthalmitis following cataract surgery at another hospital. The emergency vitrectomies in these patients were performed at our hospital with the same apparatus that was found to be contaminated 2 years later. CONCLUSION: Performing a systematic environmental search for the assumed bacterial reservoir within the system of the vitrectomy apparatus finally made it possible to find and eliminate the nidus for the gram-negative rod. Molecular typing demonstrated that all isolates belonged to a single genotype, and revealed unexpectedly a link to two vitrectomies performed 2 years earlier. The data support the hypothesis that the source of the contamination was one of these patients, and thus contamination of the apparatus was present for almost 2 years.

DNA, Bacterial↗
PubMed2004

FlaC, a protein of Campylobacter jejuni TGH9011 (ATCC43431) secreted through the flagellar apparatus, binds epithelial cells and influences cell invasion.

Type III secretion systems identified in bacterial pathogens of animals and plants transpose effectors and toxins directly into the cytosol of host cells or into the extracellular milieu. Proteins of the type III secretion apparatus are conserved among diverse and distantly related bacteria. Many type III apparatus proteins have homologues in the flagellar export apparatus, supporting the notion that type III secretion systems evolved from the flagellar export apparatus. No type III secretion apparatus genes have been found in the complete genomic sequence of Campylobacter jejuni NCTC11168. In this study, we report the characterization of a protein designated FlaC of C. jejuni TGH9011. FlaC is homologous to the N- and C-terminus of the C. jejuni flagellin proteins, FlaA and FlaB, but lacks the central portion of these proteins. flaC null mutants form a morphologically normal flagellum and are highly motile. In wild-type C. jejuni cultures, FlaC is found predominantly in the extracellular milieu as a secreted protein. Null mutants of the flagellar basal rod gene (flgF) and hook gene (flgE) do not secrete FlaC, suggesting that a functional flagellar export apparatus is required for FlaC secretion. During C. jejuni infection in vitro, secreted FlaC and purified recombinant FlaC bind to HEp-2 cells. Invasion of HEp-2 cells by flaC null mutants was reduced to a level of 14% compared with wild type, suggesting that FlaC plays an important role in cell invasion.

Bacterial Adhesion↗
PubMed1980

A flow-quench apparatus for cryoenzymic studies. Application to the creatine kinase reaction.

The flow-quench method was adapted to sub-zero conditions. Two apparatus were constructed: a rapid flow-quench apparatus (which take samples in the 5--300-ms time range) and a time delay flow-quench apparatus (0.5 s and longer). The apparatus were constructed so that the reagents are only in contact with chemically inert materials : glass, poly(tetrafluoroethylene) and poly(trifluorochloroethylene). The modified flow-quench apparatus were used to study the initial formation of creatine phosphate by creatine kinase at -15 degrees C in the time range 5 ms to 10 s. As at +4 degrees C [Travers, F., Barman, T. E. and Bertrand, R. (1979) Eur. J. Biochem. 100, 149--155], the time course of product formation was complex and consisted of three phase: a lag phase, a burst phase and the steady-state phase. The apparatus were also used to test chemically for reaction intermediates involving labile phosphate and phospho-enzyme complexes on the creatine kinase reaction pathway at -15 degrees C. Since neither type of intermediate could be detected down to 5 ms, this enzyme probably proceeds via a direct in-line type of mechanism.

Animals↗
PubMed2003

Translocated intimin receptor and its chaperone interact with ATPase of the type III secretion apparatus of enteropathogenic Escherichia coli.

Few interactions have been reported between effectors and components of the type III secretion apparatus, although many interactions have been demonstrated between type III effectors and their cognate chaperones. It is thought that chaperones may play a role in directing effectors to the type III secretion apparatus. The ATPase FliI in the flagellar assembly apparatus plays a pivotal role in interacting with other components of the apparatus and with substrates of the flagellar system. We performed experiments to determine if there were any interactions between the effector Tir and its chaperone CesT and the type III secretion apparatus of enteropathogenic Escherichia coli (EPEC). Specifically, based on analogies with the flagella system, we examined Tir-CesT interactions with the putative ATPase EscN. We showed by affinity chromatography that EscN and Tir bind CesT specifically. Tir is not necessary for CesT and EscN interactions, and EscN binds Tir specifically without its chaperone CesT. Moreover, Tir directly binds EscN, as shown via gel overlay and enzyme-linked immunosorbent assay, and coimmunoprecipitation experiments revealed that Tir interacts with EscN inside EPEC. These data provide evidence for direct interactions between a chaperone, effector, and type III component in the pathogenic type III secretion system and suggest a model for Tir translocation whereby its chaperone, CesT, brings Tir to the type III secretion apparatus by specifically interacting with the type III ATPase EscN.

Adenosine Triphosphatases↗
PubMed1989

Temperature-controlled perfusion apparatus for microscope using transparent conducting film heater.

We describe a novel temperature-controlled perfusion apparatus for electrophysiological studies on isolated cells or membrane patches. The apparatus uses a transparent conducting film of indium-tin-oxide as a heating element. The film heater deposited on a glass sheet allows us to construct a structurally simple apparatus that is able not only to heat directly the bath chamber but also to preheat the perfusion solution on the stage of an inverted microscope. The structure ensures a uniform temperature in a bath chamber that has a working area of approximately 6 X 12 mm2 and a capacity of 1 ml. A control unit, designed for operation of the apparatus, regulates the temperature of the bathing solution without introducing electrical noise in a range from ambient temperature to greater than 37 degrees C with an accuracy within +/- 1 degree C. The apparatus is 12 mm in height and designed to fit on the stage of a standard inverted microscope. Since the bath chamber for perfusion experiments is readily interchanged with others, the apparatus can be used widely in microscopic studies of various cells in static solutions.

Cell Membrane↗
PubMed2004

The ultrastructure of the Chlamydomonas reinhardtii basal apparatus: identification of an early marker of radial asymmetry inherent in the basal body.

The biflagellate unicellular green alga Chlamydomonas reinhardtii is a classic model organism for the analysis of flagella and their organizers, the basal bodies. In this cell, the two flagella-bearing basal bodies, along with two probasal bodies and an array of fibers and microtubules, form a complex organelle called the basal apparatus. The ultrastructure of the basal apparatus was analysed in detail by serial thin-section electron microscopy of isolated cytoskeletons and several newly discovered features are described, including a marker for the rotational asymmetry inherent in the basal bodies and probasal bodies. In addition, the complex three-dimensional basal apparatus ultrastructure is resolved and illustrated, including the attachment sites of all basal apparatus elements to specific microtubular triplets of the basal bodies and probasal bodies. These data will facilitate both the localization of novel basal apparatus proteins and the analysis of mutants and RNA interference cells with only subtle defects in basal apparatus ultrastructure. The early harbinger of radial asymmetry described here could play a crucial role during basal body maturation by orienting the asymmetric attachment of the various associated fibers and therefore might define the orientation of the basal bodies and, ultimately, the direction of flagellar beating.

Animals↗
PubMed1971

Behavioral engineering: two apparatuses for toilet training retarded children.

Daytime incontinence is a major problem for retarded children. A training procedure for eliminating this problem should be facilitated by an apparatus that provided the trainer with an immediate signal when the child voided so that the trainer could react immediately. Two apparatuses were developed for this purpose: a toilet-chair apparatus to signal proper toileting and a portable pants-alarm apparatus to signal wetting of the pants. A reprimand was given when pants wetting occurred whereas positive reinforcement was given for proper toileting. Results with four profoundly retarded children indicated the reliability of the apparatuses in practice and the effectiveness of a toilet training program that used the two apparatuses.

Journal Article↗
PubMed1989

Histologic evaluation of new attachment apparatus formation in humans. Part I.

Part I of this three-part human study evaluated the formation of a new attachment apparatus (bone, cementum, and periodontal ligament) on pathologically exposed root surfaces in an open and closed environment. The most apical level of calculus on the root served as a histologic reference point to measure regeneration on root surfaces exposed to the oral environment. Attempts were made to initiate the formation of a new attachment apparatus by flap curettage, root planing, coronectomy, and submersion of vital roots beneath the mucosa. Nonsubmerged defects were treated by the same surgical technique and served as controls. Biopsies were obtained at 6 months and regeneration was evaluated histometrically by two investigators who were unaware of the treatment performed. Data from 9 patients with 25 submerged and 22 nonsubmerged defects were submitted for statistical analysis. Results indicate that a new attachment apparatus did not form in any of the 22 nonsubmerged teeth; a new attachment apparatus did form in a submerged environment (0.75 mm); significantly more new attachment apparatus (P less than 0.05), new cementum (P less than 0.01), new connective tissue (P less than 0.05), and new bone (P less than 0.02) formed in submerged defects; new cementum was cellular in nature and formed equally well on old cementum and dentin. Greater percent positive regeneration of the attachment apparatus and all component tissues occurred in submerged defects and no extensive root resorption, ankylosis, or pulp death was observed on submerged or nonsubmerged roots.

Analysis of Variance↗
PubMed1989

Histologic evaluation of new attachment apparatus formation in humans. Part III.

There is still controversy as to the role of bone grafting materials in the formation of a new attachment apparatus and component tissues (bone, cementum, and periodontal ligament). The purpose of this study was to compare the healing of intrabony defects with and without the placement of decalcified freeze-dried bone allograft (DFDBA) in a nonsubmerged environment in humans. The most apical level of calculus on the root served as a histologic reference point to delineate root surfaces exposed to the oral environment and to measure new attachment apparatus and new component tissue formation. Free gingival grafts were placed over grafted and nongrafted defects to retard epithelial migration. Biopsies were obtained at 6 months and regeneration was evaluated histometrically. Data from 12 patients with 32 grafted and 25 nongrafted defects were submitted for statistical analysis. Results indicate that in nongrafted defects, a long junctional epithelium formed along the entire length of exposed root surfaces and often extended apical to the calculus reference notch. Free gingival grafts did not enhance regeneration of a new attachment apparatus, new cementum, new connective tissue, or new bone in nongrafted defects. The formation of a new attachment apparatus was observed when intrabony defects were grafted with DFDBA (x1.21 mm); significantly more new attachment apparatus (P less than .005), new cementum (P less than .005), new connective tissue (P less than .05), and new bone (P less than .0001) formed in intrabony defects grafted with DFDBA than in nongrafted defects. There was a greater chance for regeneration of a new attachment apparatus and component tissues in grafted defects than in nongrafted defects. New cellular cementum formed on old cementum and dentin but more often formed over both in the same defect). The periodontal ligament was more frequently oriented perpendicular to the root; there was greater loss in alveolar crest height in nongrafted than grafted defects (P less than .05); and extensive root resorption, ankylosis, and pulp death were not observed in grafted or nongrafted defects.

Analysis of Variance↗