A novel mathematical modeling with solution for movement of fluid through ciliary caused metachronal waves in a channel

In the present research, a novel mathematical model for the motion of cilia using non-linear rheological fluid in a symmetric channel is developed. The strength of analytical perturbation technique is employed for the solution of proposed physical process using mectachoronal rhythm based on Cilia induced flow for pseudo plastic nano fluid model by considering the low Reynolds number and long wave length approximation phenomena. The role of ciliary motion for the fluid transport in various animals is explained. Analytical expressions are gathered for stream function, concentration, temperature profiles, axial velocity, and pressure gradient. Whereas, transverse velocity, pressure rise per wave length, and frictional force on the wall of the tubule are investigated with aid of numerical computations and their outcomes are demonstrated graphically. A comprehensive analysis for comparison of Perturb and numerical solution is done. This analysis validates the analytical solution.

Optimal ciliary locomotion of axisymmetric microswimmers

Many biological microswimmers locomote by periodically beating the densely packed cilia on their cell surface in a wave-like fashion. While the swimming mechanisms of ciliated microswimmers have been extensively studied both from the analytical and the numerical point of view, optimisation of the ciliary motion of microswimmers has received limited attention, especially for non-spherical shapes. In this paper, using an envelope model for the microswimmer, we numerically optimise the ciliary motion of a ciliate with an arbitrary axisymmetric shape. Forward solutions are found using a fast boundary-integral method, and the efficiency sensitivities are derived using an adjoint-based method. Our results show that a prolate microswimmer with a $2\,{:}\,1$ aspect ratio shares similar optimal ciliary motion as the spherical microswimmer, yet the swimming efficiency can increase two-fold. More interestingly, the optimal ciliary motion of a concave microswimmer can be qualitatively different from that of the spherical microswimmer, and adding a constraint to the cilia length is found to improve, on average, the efficiency for such swimmers.

Using Paramecium as a Model for Ciliopathies

Paramecium has served as a model organism for the studies of many aspects of genetics and cell biology: non-Mendelian inheritance, genome duplication, genome rearrangements, and exocytosis, to name a few. However, the large number and patterning of cilia that cover its surface have inspired extraordinary ultrastructural work. Its swimming patterns inspired exquisite electrophysiological studies that led to a description of the bioelectric control of ciliary motion. A genetic dissection of swimming behavior moved the field toward the genes and gene products underlying ciliary function. With the advent of molecular technologies, it became clear that there was not only great conservation of ciliary structure but also of the genes coding for ciliary structure and function. It is this conservation and the legacy of past research that allow us to use Paramecium as a model for cilia and ciliary diseases called ciliopathies. However, there would be no compelling reason to study Paramecium as this model if there were no new insights into cilia and ciliopathies to be gained. In this review, we present studies that we believe will do this. For example, while the literature continues to state that immotile cilia are sensory and motile cilia are not, we will provide evidence that Paramecium cilia are clearly sensory. Other examples show that while a Paramecium protein is highly conserved it takes a different interacting partner or conducts a different ion than expected. Perhaps these exceptions will provoke new ideas about mammalian systems.

Theoretical study of an unsteady ciliary hemodynamic fluid flow subject to the Newton’s boundary conditions

This article addresses the hemodynamic flow of biological fluid through a symmetric channel. Methachronal waves induced by the ciliary motion of motile structures are the main source of Couple stress nanofluid flow. Darcy’s law is incorporated in Navier-Stokes equations to highlight the influence of the porous medium. Thermal transport by the microscopic collision of particles is governed by Fourier’s law while a separate expression is obtained for net diffusion of nanoparticles by using Fick’s law. A closed-form solution is achieved of nonlinear differential equations subject to Newton’s boundary conditions. Moreover, the current findings are compared with previous outcomes for the limiting case and found a complete coherence. Parametric study reveals that nanoflow is resisted by employing Newton’s boundary conditions. Thermal profile enhancement is contributed by the viscous dissipation parameter. Finally, one infers that hemodynamic flow of non-Newtonian fluid is an effective mode of heat and mass transfer especially, in medical sciences for the rapid transport of medicines in drug therapy.

Tracheal motile cilia in mice require CAMSAP3 for formation of central microtubule pair and coordinated beating

Motile cilia of multiciliated epithelial cells undergo synchronized beating to produce fluid flow along the luminal surface of various organs. Each motile cilium consists of an axoneme and a basal body, which are linked by a ‘transition zone’. The axoneme exhibits a characteristic 9+2 microtubule arrangement important for ciliary motion, but how this microtubule system is generated is not yet fully understood. Here we show that CAMSAP3, a protein that can stabilize the minus end of a microtubule, concentrates at multiple sites of the cilium–basal body complex, including the upper region of the transition zone or the axonemal basal plate where the central pair of microtubules (CP) initiates. CAMSAP3 dysfunction resulted in loss of the CP and partial distortion of the basal plate, as well as the failure of multicilia to undergo synchronized beating. These findings suggest that CAMSAP3 plays pivotal roles in the formation or stabilization of the CP by localizing at the basal region of the axoneme, and thereby supports the coordinated motion of multicilia in airway epithelial cells. [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text] [Media: see text]

Ependymal ciliary motion and their role in congenital hydrocephalus

Purpose Since a case of hydrocephalus in humans considered to be caused by ciliary dysfunction was first reported by Greenstone et al. in 1984, numerous papers on the correlation between ciliary function and hydrocephalus have been published. Methods We reviewed the published literature on primary ciliary dyskinesia in humans causing hydrocephalus, focusing on articles specifically examining the relation between ciliary function and hydrocephalus and its treatment. In addition, the authors’ experience is briefly discussed. Results Full texts of 16 articles reporting cases of human hydrocephalus (including ventriculomegaly) due to defects in ependymal ciliary function or primary ciliary dyskinesia observed in clinical practice were extracted. In recent years, studies on animal models, especially employing knockout mice, have revealed genetic mutations that cause hydrocephalus via ciliary dysfunction. However, a few reports on the onset of hydrocephalus in human patients with primary ciliary dyskinesia have confirmed that the incidence of this condition was extremely low compared to that in animal models. Conclusion In humans, it is rare for hydrocephalus to develop solely because of abnormalities in the cilia, and it is highly likely that other factors are also involved along with ciliary dysfunction.

Tracheal motile cilia require CAMSAP3 for formation of central microtubule pair and coordinated beating

Motile cilia of multiciliated epithelial cells undergo synchronized beating to produce fluid flow along the luminal surface of various organs. Each motile cilium consists of an axoneme and a basal body, which are linked by a ‘transition zone’. The axoneme exhibits a characteristic 9+2 microtubule arrangement important for ciliary motion, but how this microtubule system is generated is not yet fully understood. Here, using superresolution microscopy, we show that CAMSAP3, a protein that can stabilize the minus end of a microtubule, concentrates at multiple sites of the cilium-basal body complex, including the upper region of the transition zone or the axonemal basal plate where the central pair of microtubules (CP) terminates. CAMSAP3 dysfunction resulted in loss of the CP and partial distortion of the basal plate, as well as the failure of multicilia to undergo synchronized beating. These findings indicate that CAMSAP3 plays pivotal roles in the formation or stabilization of the CP, and thereby supports the coordinated motion of multicilia in airway epithelial cells.

Investigation of electroosmosis flow of copper nanoparticles with heat transfer due to metachronal rhythm

A mathematical model is explored to establish the electroosmotic flow for Cu-wa-ter nanoliquids within a ciliated symmetric micro-channel, the flow is established with aid of ciliary motion and axial pressure gradient. Nanofluid comprise of Cu as a nanofluid particles and water as base fluid. Maxwell-Garnelt model is exploited for viscosity and thermal conductivity of nanoliquid. Magnetic field is applied in the transverse direction and external electric field is enforced in the axial direction. Equations of motion are simplified for nanofluid flow in the micro-channel by employing low Reynolds number and long wavelength approximation theory. Crucial exact analytical expression are gathered for electric potential, temperature profile, axial velocity, volume flux, pressure gradient, stream function, and result for pressure rise per wavelength explored numerically. The influence of crucial flow parameters on, flow behaviour, pumping phenomena, and temperature profile are thoroughly investigated.

In vivo and in vitro observation of nasal ciliary motion in a guinea pig model

In vitro airway specimens are widely used to evaluate airway ciliary function. However, the function of in vitro ciliated cells may be far different from their actual in vivo physiological conditions. Due to the lack of a valid technique, direct images of in vivo airway ciliary motion have never been captured and analyzed before. This study aims to examine nasal ciliary motion in living guinea pigs with comparison to in vitro observation. Nasal septum mucosa was exposed in anaesthetized guinea pigs and directly examined using a digital microscopy system. The study included three parts: (1) measurement of ciliary beat frequency (CBF) of nasal mucosa at room temperature in living guinea pigs and immediately after death, and in dissected mucosa specimens/cells for comparison; (2) monitoring of nasal ciliary motion, CBF, and ciliary beat distance (CBD) over 12 h in both living guinea pigs and dissected mucosa specimens/cells; and (3) measurement of ciliary motion changes in responses to temperature variations. Compared with when the animal was alive, the CBF after death and in dissected mucosa specimens/cells was lower by about 20% ( P < 0.05). CBF and CBD variation in living guinea pigs was within 10% over time. The slope of CBF/temperature profile was 0.18 ± 0.01 Hz/°C in living guinea pigs, 0.51 ± 0.02 Hz/°C for dissected mucosa specimens, and 0.48 ± 0.03 Hz/°C for isolated ciliary cells. The technique described in this study makes it feasible to study ciliary motion in living animals using the digital microscope system. Ciliary function changes immediately after death. Ciliary motion in a living animal is more stable over time and has a different response to temperature change as compared with in vitro observation results. Impact statement Cilia play an important role in the airway defense mechanism. So far, studies on ciliary function have mainly been based on in vitro methods. Images of in vivo ciliary motion are very difficult to capture. In this study, we describe a novel approach to observe and analyze nasal ciliary motion in living animals with comparison to in vitro observation. Such images of ciliary motion from living animals have not been reported to date. The result of the study indicates that in vivo ciliary physiological function differs from ex vivo and in vitro conditions in many ways, such as the stability over time and response to temperature variation. This is a good foundation for further in vivo analysis of airway ciliary physiological function in animals as well as humans.