scholarly journals Polymorphism in a Flagellar-shape Mutant of Salmonella typhimurium

Microbiology ◽  
2000 ◽  
Vol 81 (1) ◽  
pp. 37-45 ◽  
Author(s):  
T. Iino ◽  
Tomoko Oguchi ◽  
T. Kuroiwa
Keyword(s):  
Salmonella Typhimurium ◽  
Phosphotungstic Acid ◽  
Phase 1 ◽  
Marked Change ◽  
Uranyl Acetate ◽  
Negative Staining ◽  
Wave Form ◽  
Specimen Preparation ◽  
Physico Chemical ◽  
Wave Forms

A flagellar-shape mutant, designated ‘polymorphous’, was isolated from a normal flagella strain of Salmonella typhimurium. The mutant produces normal flagella in phase 1 and polymorphous flagella in phase 2. The polymorphous flagella are either straight or possess one of the four distinct wave-forms, namely M, S, N or C, when observed with an electron microscope after negative staining with phosphotungstic acid or uranyl acetate. Conversions between the four wave-forms were found to be brought about mainly by a change in the degree of twisting of longitudinal strands around the axis of a flagella filament, without marked change in the relative lengths of the outermost and innermost strands. The major fraction of the polymorphous mutant flagella showed the N-form under any conditions of specimen preparation. The remaining four forms appeared as minor fractions in various proportions. Specimens fixed with formalin showed less pronounced polymorphism than unfixed ones. Negative staining with uranyl acetate was more effective than with phosphotungstic acid for observing polymorphism. Even though more than one form appeared among the polymorphous flagella, each individual flagellum comprised a single form except for a rare coexistence of S and N. The same form of flagella tended to coexist in a bacterium in a heteromorphously flagellated cell population. It was concluded that the conformation and arrangement of the flagellin molecules responsible for wave-form result from strong mutual interactions between the neighbouring molecules along the flagellar filaments and also, to a lesser extent, between the neighbouring filaments in a flagellar bundle, as well as being influenced by the physico-chemical environment.

Ultrastructure and Staining of Developing Elastic Tissue

1971 ◽  
Vol 29 ◽  
pp. 244-245
Author(s):  
E. N. Albert
Keyword(s):  
Fine Structure ◽  
Phosphotungstic Acid ◽  
Staining Method ◽  
Rat Aorta ◽  
Uranyl Acetate ◽  
The Other ◽  
Elastic Fibers ◽  
Elastic Tissue ◽  
Lead Citrate ◽  
New Born

Silver tetraphenylporphine sulfonate (Ag-TPPS) was synthesized in this laboratory and used as an electron dense stain for elastic tissue (Fig 1). The procedures for the synthesis of tetraphenylporphine sulfonate and the staining method for mature elastic tissue have been described previously.The fine structure of developing elastic tissue was observed in fetal and new born rat aorta using tetraphenylporphine sulfonate, phosphotungstic acid, uranyl acetate and lead citrate. The newly forming elastica consisted of two morphologically distinct components. These were a central amorphous and a peripheral fibrous. The ratio of the central amorphous and the peripheral fibrillar portion changed in favor of the former with increasing age.It was also observed that the staining properties of the two components were entirely different. The peripheral fibrous component stained with uranyl acetate and/or lead citrate while the central amorphous portion demonstrated no affinity for these stains. On the other hand, the central amorphous portion of developing elastic fibers stained vigorously with silver tetraphenylporphine sulfonate, while the fibrillar part did not (compare figs 2, 3, 4). Based upon the above observations it is proposed that developing elastica consists of two components that are morphologically and chemically different.

Identification of the pulmonary syndrome hantavirus by direct and colloidal gold immune Electron Microscopy

1994 ◽  
Vol 52 ◽  
pp. 274-275
Author(s):  
C. D. Humphrey ◽  
C.S. Goldsmith ◽  
L. Elliott ◽  
S.R. Zaki
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Monoclonal Antibody ◽  
Colloidal Gold ◽  
Phosphotungstic Acid ◽  
Uranyl Acetate ◽  
Hantavirus Pulmonary Syndrome ◽  
Deer Mice ◽  
Immune Electron Microscopy ◽  
Negative Stain

An outbreak of unexplained acute pulmonary syndrome with high fatality was recognized in the spring of 1993 in the southwestern United States. The cause of the illness was quickly identified serologically and genetically as a hantavirus and the disease was named hantavirus pulmonary syndrome (HPS). Recently, the virus was isolated from deer mice which had been trapped near the homes of HPS patients, and cultivated in Vero E6 cells. We identified the cultivated virus by negative-stain direct and colloidal gold immune electron microscopy (EM).Virus was extracted, clarified, and concentrated from unfixed and 0.25% glutaraldehyde fixed supernatant fluids of infected Vero E6 cells by a procedure described previously. Concentrated virus suspensions tested by direct EM were applied to glow-discharge treated formvar-carbon filmed grids, blotted, and stained with 0.5% uranyl acetate (UA) or with 2% phosphotungstic acid (PTA) pH 6.5. Virus suspensions for immune colloidal gold identification were adsorbed similarly to filmed grids but incubated for 1 hr on drops of 1:50 diluted monoclonal antibody to Prospect Hill virus nucleoprotein or with 1:50 diluted sera from HPS virus infected deer mice.

A combined pseudoreplica-immunocytochemical technique for research and diagnostic virology

1990 ◽  
Vol 48 (3) ◽  
pp. 900-901
Author(s):  
Blayne Fritz ◽  
Stanley J. Naides ◽  
Kenneth Moore
Keyword(s):  
Phosphotungstic Acid ◽  
Immunogold Labelling ◽  
Uranyl Acetate ◽  
Distilled Water ◽  
Clinical Specimens ◽  
Tissue Sections ◽  
Specimen Retrieval ◽  
Transmission Electron ◽  
Viral Particles ◽  
Diagnostic Virology

The pseudoreplica method of staining viral particles for visualization by transmission electron microscopy is a very popular technique. The ability to concentrate clinical specimens while semi-embedding viral particles makes it especially well suited for morphologic and diagnostic virology. Immunolabelling viral particles with colloidal gold is a technique frequently employed by both research and diagnostic virologists. We have characterized a procedure which provides the advantage of both by modifying and combining pseudoreplica staining and immunogold labelling.Modification of specimen retrieval and delay of staining allows us to utilize pseudoreplica processed specimens within our standard immunogold labelling protocol. In brief, we absorbed samples onto 2% agarose, added.25% Formvar and wicked dry. We then floated the Formvar-virus film onto double distilled water, added grids and retrieved with parafilm. The Formvar-virus specimens were then treated as thin tissue sections within our standard two stage immunolabelling protocol. Following completion of immunogold labelling; each grid was negatively stained with phosphotungstic acid or uranyl acetate contrast stains.

Sequence analysis of operator mutants of the phase-1 flagellin-encoding gene, flic, in salmonella typhimurium

Gene ◽  
1989 ◽  
Vol 85 (1) ◽  
pp. 221-226 ◽  
Author(s):  
Yoshihiro H. Inoue ◽  
Kazuhiro Kutsukake ◽  
Tetsuo Iino ◽  
Shigeru Yamaguchi
Keyword(s):  
Sequence Analysis ◽  
Salmonella Typhimurium ◽  
Phase 1 ◽  
Encoding Gene

Elastic displacements in the near-field of a propagating fault

1969 ◽  
Vol 59 (2) ◽  
pp. 865-908
Author(s):  
N. A. Haskell
Keyword(s):  
Fault Plane ◽  
Near Field ◽  
Strong Motion ◽  
Dislocation Motion ◽  
Displacement Discontinuity ◽  
Wave Form ◽  
Strong Motion Station ◽  
Ramp Function ◽  
Wave Forms ◽  
Parkfield Earthquake

abstract Displacement, particle velocity, and acceleration wave forms in the near field of a propagating fault have been computed by numerical integration of the Green's function integrals for an infinite medium. The displacement discontinuity (dislocation) on the fault plane is assumed to have the form of a unilaterally propagating finite ramp function in time. The calculated wave forms in the vicinity of the fault plane are quite similar to those observed at the strong motion station nearest the fault plane at the Parkfield earthquake. The comparison suggests that the propagating ramp time function is roughly representative of the main features of the dislocation motion on the fault plane, but that the actual motion has somewhat more high frequency complexity. Calculated amplitudes indicate that the average final dislocation on the fault at the Parkfield earthquake was more than an order of magnitude greater than the offsets observed on the visible surface trace. Computer generated wave form plots are presented for a variety of locations with respect to the fault plane and for two different assumptions on the relation between fault length and ramp function duration.

Some numerical solutions for Lamb's problem

1974 ◽  
Vol 64 (2) ◽  
pp. 473-491
Author(s):  
Harold M. Mooney
Keyword(s):  
Rayleigh Wave ◽  
Poisson’S Ratio ◽  
Pulse Width ◽  
Numerical Solutions ◽  
Pulse Height ◽  
P Wave ◽  
Poisson's Ratio ◽  
Wave Form ◽  
Lamb’S Problem ◽  
Wave Forms

abstract We consider a version of Lamb's Problem in which a vertical time-dependent point force acts on the surface of a uniform half-space. The resulting surface disturbance is computed as vertical and horizontal components of displacement, particle velocity, acceleration, and strain. The goal is to provide numerical solutions appropriate to a comparison with observed wave forms produced by impacts onto granite and onto soil. Solutions for step- and delta-function sources are not physically realistic but represent limiting cases. They show a clear P arrival (larger on horizontal than vertical components) and an obscure S arrival. The Rayleigh pulse includes a singularity at the theoretical arrival time. All of the energy buildup appears on the vertical components and all of the energy decay, on the horizontal components. The effects of Poisson's ratio upon vertical displacements for a step-function source are shown. For fixed shear velocity, an increase of Poisson's ratio produces a P pulse which is larger, faster, and more gradually emergent, an S pulse with more clear-cut beginning, and a much narrower Rayleigh pulse. For a source-time function given by cos2(πt/T), −T/2 ≦ T/2, a × 10 reduction in pulse width at fixed pulse height yields an increase in P and Rayleigh-wave amplitudes by factors of 1, 10, and 100 for displacement, velocity and strain, and acceleration, respectively. The observed wave forms appear somewhat oscillatory, with widths proportional to the source pulse width. The Rayleigh pulse appears as emergent positive on vertical components and as sharp negative on horizontal components. We show a theoretical seismic profile for granite, with source pulse width of 10 µsec and detectors at 10, 20, 30, 40, and 50 cm. Pulse amplitude decays as r−1 for P wave and r−12 for Rayleigh wave. Pulse width broadens slightly with distance but the wave form character remains essentially unchanged.

STUDIES OF DISTAL COLONIC MOTILITY IN CHILDREN

PEDIATRICS ◽  
1956 ◽  
Vol 17 (6) ◽  
pp. 820-833
Author(s):  
Murray Davidson ◽  
Marvin H. Sleisenger ◽  
Thomas P. Almy ◽  
Samuel Z. Levine
Keyword(s):  
Ulcerative Colitis ◽  
Bowel Movement ◽  
Colonic Motility ◽  
Distal Colon ◽  
Wave Form ◽  
Spontaneous Bowel Movement ◽  
Normal Individuals ◽  
Iced Water ◽  
Wave Forms

A characteristic propulsive wave, previously reported in adults with ulcerative colitis, has been found in infants with acute diarrhea but not in children with ulcerative colitis. The reasons for this are discussed. The induction of propulsive wave forms in normal individuals by administration of magnesium sulfate orally is described and attention is called to its application to therapeutic studies. The relation of this wave form to propulsion of fecal contents and defecation and its role in the production of abdominal discomfort are considered. Observed variations in the responses of individual children to subcutaneous injection of Mecholyl®, to oral administration of iced water, and to rectal distention may explain innate differences in susceptibility to the development of colonic symptoms in different children. A classification of wave forms from the distal colon based on current concepts of their probable physiologic significance is offered. A tracing from the distal colon in a child having a spontaneous bowel movement is presented and commented on.

Bioelectric Regulation of Tentacle Movement in a Dinoflagellate

1967 ◽  
Vol 47 (3) ◽  
pp. 433-446
Author(s):  
ROGER ECKERT ◽  
TAKAO SIBAOKA
Keyword(s):  
Temporal Relationship ◽  
Sea Water ◽  
Outward Current ◽  
Wave Form ◽  
Applied Current ◽  
Inward Current ◽  
Wave Forms ◽  
Noctiluca Miliaris ◽  
Spike Wave ◽  
Peripheral Cytoplasm

1. Recurring extensions and flexions of the food-gathering tentacle of Noctiluca miliaris occur spontaneously. Identical movements can be evoked by appropriate electrical stimulation. 2. Spontaneous recurring potential wave forms (TRPs) were recorded from the vacuole of the luminescent form of Noctiluca during movements of the tentacle. The basic TRP wave form consists of a characteristic negative-going spike which arises at -20 to -30 mV. from the slowly redeveloping negativity of a pre-spike depolarization, and is followed by a quasi-stable post-spike d.c. level of relative vacuolar negativity (-45 to -60 mV.). 3. The TRP complex, similar in shape to that which occurs spontaneously, follows an intracellularly applied current pulse of either polarity if the vacuolar potential is at the post-spike level. The duration of the evoked pre-spike wave is related to the current intensity and duration. During the pre-spike state outward current is ineffective, although a TR spike occurs in response to inward current. 4. The TRP is distinct in its behaviour and wave form from the flash-triggering potential, which can be evoked in the same cell, even though both exhibit all-or-none spikes. 5. Simultaneous recordings of intracellular potentials and movements of the tentacle showed a consistent temporal relationship between potential changes and subsequent movement. Extension of the tentacle begins 1-2 sec. after the spike and flexion begins within 1 sec. after beginning of the pre-spike wave. 6. Tentacle movement ceased in Ca-free sea water even though the cyclic potential changes continued normally. 7. Electron micrographs of the tentacle showed longitudinal aggregations of microtubules near the outer surface of the peripheral cytoplasm. It is proposed that contraction of these microtubules is the immediate cause of tentacle movements.

Effect of Forcing Terms and General Characteristics of Torsional Vibrations of Marine Engine Systems with Variable Inertia

1974 ◽  
Vol 18 (02) ◽  
pp. 131-138
Author(s):  
W. D. Carnegie ◽  
M. S. Pasricha
Keyword(s):  
Equations Of Motion ◽  
Mean Value ◽  
Wave Form ◽  
Actual System ◽  
Computer Methods ◽  
Reciprocating Engine ◽  
Complex Wave ◽  
Wave Forms ◽  
Crankshaft Rotation ◽  
Engine Systems

The torsional vibration phenomenon in the running gear of reciprocating engine systems is usually dealt with by considering a series of constant inertias connected by sections of massless shafting. Such a simplified model does not reproduce the exact dynamic characteristics of the actual system. In recent years several cases of marine crankshaft failures have been attributed to the phenomenon of secondary resonance, which is explained by the fact that the effective inertia of each slider crankmechanism varies about a mean value in relation to the position of the crank. When the variableinertia effect is allowed for, the equations of motion taking into account the effect are nonlinear. Assuming small displacements, the equations can be linearized to predict important characteristics of the motion. The motions in the form of complex wave forms are studied at different speeds of engine rotation and some of the wave form solutions are analyzed in the range of present investigations. Computer methods making use of numerical analysis processes, namely, the modifiedEuler's equations and the Runge-Kutta constants, have been applied in the investigations. A study of the effect on the motion of the system due to variation of inertia ratio is carried out at a particular speed of the crankshaft rotation; also investigated are the variations in the motions due to the action of external excitations with respect to changes in phase angle and inertia ratio. General comments on Draminsky's work in the light of the present investigations are included.

Uterine work in parturition

1976 ◽  
Vol 41 (3) ◽  
pp. 316-322 ◽  
Author(s):  
T. J. Kriewall
Keyword(s):  
Viscoelastic Model ◽  
Geometrical Model ◽  
Clinical Findings ◽  
Cervical Dilatation ◽  
Wave Form ◽  
Intrauterine Pressure ◽  
Wave Forms ◽  
Internal Volume ◽  
Synergistic Relationship ◽  
Incremental Volume

This paper presents a theoretical analysis relating work expended by the uterus to the synergistic relationship between intrauterine pressure (IUP) and cervical dilatation (CD). By utilizing a geometrical model for the fetal presenting part which is assumed to be in contact with the cervix, the changes in internal volume of the uterus with each contraction can be shown to be functionally related to cervical dilatation. Thus work, expressed in terms of foot-pounds, can be calculated using the integral of pressure times incremental volume. By simulating intrauterine pressure and cervical dilatation with continuous analytical wave forms, the alterations required in uterine work to dilate the cervix are calculated for various wave-form aberrations which are seen in clinical situations. The wave-form aberrations are applied to an elastic cervical model as well as a viscoelastic model. Using the principles of thermodynamics the areas of the fetouterine complex which absorb the work generated by the contractions are defined. It is shown that the efficiency of the contractions to dilate the cervix can be calculated by evaluating the work expended in these various areas of energy absorption. The purpose of this paper is to present the theory upon which clinical findings in obstetrics can be based so that conclusions drawn will be technically sound.

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