Theodore L. Jahn

Demonstration of serum protein differences in cystic fibrosis by isoelectric focusing in thin-layer polyacrylamide gels

Abstract Whole serum samples from cystic fibrosis patients, heterozygotes and normal individuals were analyzed using isoelectric focusing in thin-layer polyacrylamide gels. Using this technique consistent serum protein differences between the three serum types have been demonstrated. A protein with an isoelectric point of 5.48 ± 0.1 was found in 14 out of 17 normal sera and in all heterozygote sera tested but not in 15 out of 16 cystic fibrosis sera tested. A protein with an isoelectric point of 8.41 ± 0.1 was found in 12 out of 13 cystic fibrosis sera and all heterozygote sera but not in 11 out of 12 normal sera tested. The concentration of both of these proteins was demonstrated to be variable among the heterozygotes as shown by electrofocusing of different volumes of serum. Partial characterization of both proteins was achieved using the combined techniques of isoelectric focusing, immunoelectrophoresis, acrylamide to ionagar electrophoresis, ammonium sulfate precipitation and diethylaminoethylcellulose chromatography (pH 8.0). The protein with an isoelectric point at pH 5.48 ± 0.1 was found to be a heat labile beta-globulin and the protein with an isoelectric point of 8.41 ± 0.1 was found to be a heat labile gamma-globulin. The significance of the findings are discussed.

Studies on cystic fibrosis using isoelectric focusing. I. An assay for detection of cystic fibrosis homozygotes and heterozygote carriers from serum.

Extract: We have developed a standardized biophysical assay for the rapid detection of individuals homozygous or heterozygous for cystic fibrosis (C/F). The assay employs isoelectric focusing in thin layer polyacrylamide gels to analyze microliter quantities of whole serum for the presence of a C/F factor protein and for deletions in a group of proteins called proteins B, C, and D (Fig. 1). A pH 5–10 gradient is used (Fig. 2) and each sample is screened using a serum volume which contains 300 μ g immunoglobulin G (IgG). Individuals homozygous or heterozygous for C/F are distinguished from normal unaffected individuals on the basis of the presence of a C/F factor protein band (Table 1). Heterozygous carriers for C/F are distinguished from C/F homozygotes 75% of the time, on the basis of a deletion in either band B, C, or D (Table 2).On the basis of screening 65 patients with cystic fibrosis. 61 heterozygous carriers for C/F, and 105 normal control subjects, it was concluded that no obvious correlation existed between either sex, age, or severity of the disease in the individual C/F patient, and the absolute presence or absence of the C/F factor. In addition, no correlation existed between sex or age and the presence of the C/F factor or deletions in proteins B, C, and D in the individual heterozygous carrier for C/F or normal control subjects. Analysis of serum samples from 68 patients with a variety of other diseases, many with clinical symptoms resembling those seen in the patient with cystic fibrosis (Table 3), indicated that the C/F factor protein described in this study appears to be diagnostic for C/F genotypes, with the possible exception of patients with certain types of leukemia.Speculation: The biophysical assay described in this report or a modification of it may prove to be a useful method for the routine detection of carriers of cystic fibrosis in the general population.

A theory of electronic conduction through membranes, and of active transport of ions, based on redox transmembrane potentials

Abstract It is proposed that the Lund theory that transmembrane potentials are primarily oxidation-reduction potentials be reinterpreted in terms of modern theories of electron transport in organic compounds so as to include electron flow through the lipoid substances of the membrane. It is assumed that two oxidation-reduction enzyme systems on either side of cell membranes are connected by transmembrane lipoid substances with conjugated bonds, and that electrons are transported by resonance under electronic pressure from the reactions of these enzyme systems. On the assumption that this is the primary source of electromotive force, it is then possible to explain the apparent rapid transport of H ions as being brought about by proton charge transfer through small pores filled or lined with a continuous water lattice. The less rapid transport of chloride can then be explained as resulting from electrostatic forces and taking place through other pores of a given size most selective for chloride transfer but without a continuous water lattice. Similarly, if we assume pores of a size most selective for sodium and also without a continuous water lattice, we can explain the movement of both sodium and chloride in the same direction. Whether the movement is to the positive or negative side of the membrane will depend on how closely the pores fit those ions for which they are most selective. One advantage of this theory is that it does not postulate a 1 to 1 correlation between the number of ions transported and the number of electrons produced, but only enough electromotive force to overcome friction of the ions in the pores.

Geotaxis in Protozoa I. A propulsion—gravity model for tetrahymena (Ciliata)☆

Abstract A propulsion-based model for negative geotaxis of ciliated protozoa is presented which views geotaxic reorientation as the unbalancing of gyrational torque by a sedimentation torque. The balanced gyrational torque results from the location of the propulsive center of effort forward of the body center of mass. When gravity is ignored, the propulsive forces generating the gyrational moments may be confined to an envelope surrounding the cell. The effect of gravity is to induce sedimentation of the body-plus-envelope system. Viscous resistance to this sedimentation at the envelope “surface” is transmitted to the beating cilia whose net constant energy output must now deal with a new source of dissipation (not “present” when gravity was ignored) which is maximal in the downswing portion of the gyration cycle. In such a manner sedimentation resistance acts as a counter torque to the downswing gyrational moment of force and an enhancing torque to the upswing moment thereby generating a net upward reorientation of the gyrational axis. Upon addition of the translational component of propulsion, the negative geotaxis behavior pattern is completed. The forward location of the center of effort which provides the basic validity indicator for the model is verified by observations from the ciliate Tetrahymena .

A theory of piezoelectric activity and ion-movements in the relation of flagellar structures and their movements to the phototaxis of Euglena

Abstract A review of the literature on the flagellar undulations and phototactic movements of Euglena indicates that the flagellum functions as an ATP-using motor, triggered and mediated by cations, especially H3O+, K+, Mg2+ and Ca2+, and driven by energy from ATP. The undulatory waves are assumed to be started by means of repetitive pulses due to a redox reaction at the base of the flagellum. It is also assumed that the axoneme and paraflagellar rod are composed of asymmetrically-crystalline proteinaceous fibrils which are piezoelectric, i.e. they bend when energy passes through or along them, thus acting as a motor, and when bending they deliver a current, thus acting as a generator. This piezoelectric activity displaces cations and drives them ahead of it, triggering sequential bending and straightening of segments of the flagellum from base to tip. The paraflagellar swelling (“photoreceptor”) is also assumed to be piezoelectric, reactive to light, acting as a capacitor. It discharges as the intensity of light striking it is changed by the alternative shading effect of the stigma (“eyespot”) and exposure to light as the Euglena gyrates in swimming. The charge delivered by the photoreceptor augments the effects of ion-movements along the flagellum, also augmenting the amplitude and force of the flagellar undulations and altering the position of the flagellum relative to the body and the direction of swimming. The body is tipped away from the original path and swims either toward or away from the light, depending on the ultimate alteration of the path of swimming.

Contraction of protoplasm. IV. Cinematographic analysis of the contraction of some peritrichs

The contraction of Stentor and Blepharisma, in response to mechanical and electrical stimulation and of Spirostomum in response to mechanical stimulation is described. All three species respond to electrical stimulation by contraction of the cytoplasm, beginning at the anodal end regardless of orientation of the animal. The differences in contractile ability and shapes during contraction are discussed in relation to body form and microanatomy. Stentor and Spirostomum also respond to mechanical stimulation. Dropping a weight on the slide causes contraction of the whole body of Spirostomum, but not of Stentor. Stimulation of the oral region of Stentor by means of a vibrating needle causes a contraction of the entire body, but this sensitivity is limited to the oral region. Blepharisma does not respond to mechanical stimulation. Spirostomum and Stentor undergo rapid spontaneous contractions, but Blepharisma does not contract spontaneously.

A possible mechanism for the amplifier effect in the retina

Abstract Light transforms the trans -retinene, thereby making the molecule longer and highly resonant. It is proposed that these changes permit electron flow through the lamellar membranes, with the electrons provided by and received by oxidation-reduction enzymes, one on each side of a membrane. This conductive state of retinene occurs only in the lumi- and metarhodopsins. While conductive, a molecule of retinene, under electron pressure from oxidation-reduction enzymes, might conduct many electrons, thereby providing an amplifier mechanism, and causing depolarization of the membrane.

High Speed Cinemicrographic Studies on Rabbit Tracheal (Ciliated) Epithelia: Determination of the Beat Pattern of Tracheal Cilia

Extract: High speed cinemicrographs reveal that the ciliary configuration and beat pattern of rabbit tracheal cilia differ significantly from classic descriptions, although the basic forward and return pattern is still observed. The tracheal cilia are short and stout (about 6 μm in length) and are of a slightly bent original configuration. At the start of the forward stroke, the cilia bear about 75–90° to the epithelial surface in the direction of the forward stroke. The forward stroke is planar and consists of a simple “bowing” movement, without showing any progressive bending and without changing the original ciliary configuration. The complete forward stroke sweeps through an arc of about 35–40°, with the tips of the cilia penetrating the bottom of the mucous layer through an arc of about 5–8° at the start of each forward stroke. The return stroke starts from close to the epithelial surface and returns to the starting position of the forward stroke by reversing the planer forward pathway at a reduced speed. The stout nature of the cilia, the original bent ciliary configuration, the near vertical starting position of the forward stroke, the extent of the angular sweeps of the strokes, the peculiar “bowing” forward stroke movement, and the nature of the return stroke all serve to enhance efficiency in moving fluid forward.It has been documented that each forward stroke of the tracheal cilia causes and maintains a swift forward movement of the intermediate serous (liquid) layer of the mucociliary system. This movement, in turn, reacts hydrodynamically with the top mucous layer, and together with the clawing action of the tips of the cilia at the start of the forward stroke, causes the mucous layer to move cephalad in the manner of a conveyor belt.Speculation: This research report describes a method by which the ciliary activity of live rabbit tracheal cilia is documented. The exact ciliary beat pattern can then be determined and the clearance mechanism of tracheal mucus better understood.It is speculated that tracheal mucus stagnation in cystic fibrosis may be a hydromechanical and biochemical problem rather than a direct cilia control problem. Detailed analysis of the ciliary beat pattern and mucus clearance of the tracheal mucociliary system may serve to provide a reference baseline to investigate the possible physiologic effects of cystic fibrosis serum on ciliated epithelial cells (such physiologic effects will be dealt with in a separate report).

SECRETORY ACTIVITY OF THE ORAL APPARATUS OF CILIATES: TRAILS OF ADHERENT PARTICLES LEFT BY PARAMECIUM MULTIMICRONUCLEATUM AND TETRAHYMENA PYRIFORMIS*

T r a i l s of adherent p a r t i c l e s w e r e f i r s t s e e n by us in motion ‘hpportmd bY ONR contract Nonr 233(65) and NIH grant No. 6462.

A theory for the locomotion of spirochetes

Abstract A hydrodynamic theory for the locomotion of spirochetes is presented. The theory is based on a possible arrangement of internal fibrils such that self rotation about a local body axis is possible. This self rotation is responsible for cancelling the torque produced by the traveling helical waves of the body. The hydrodynamic theory follows the method used by Taylor, but with different boundary conditions. A relationship between the radius of body cross section, amplitude and wavelength of the helical wave is obtained for a spirochete traveling with no apparent slippage of water. The angular velocity of rotation about a local body axis is also determined. The theoretical results compare favorably with direct measurements of body geometry.