Characterization of sodium transport in gustatory epithelia from the hamster and rat

The transduction of sodium salts occurs through a variety of mechanisms, including sodium influx through amiloride-sensitive sodium channels, anion-dependent sodium movement through intercellular junctions and unidentified amiloride-insensitive mechanisms. Characterizations of sodium transport in lingual epithelium mounted in Ussing chambers have focused almost exclusively on epithelia containing only fungiform taste buds. In the present study we have investigated sodium transport by measuring NaCl-induced short-circuit current from lingual epithelia containing fungiform, foliate, vallate and palatine taste buds in the hamster and the rat. All areas show measurable sodium transport, yet significant differences were noted between the epithelia from the rat and the hamster and among the different epithelia within a single species in terms of current density, transepithelial resistance and mucosal amiloride sensitivity. In general, epithelia from the anterior tongue were of a lower resistance and transported sodium more effectively than from the posterior tongue. Moreover, fungiform- and vallate-containing epithelia in the rat had a greater current density than did the corresponding tissues in the hamster. Amiloride sensitivity also differed between the rat and the hamster. In the hamster all gustatory areas showed some amiloride sensitivity, while in the rat the vallate-containing epithelia were devoid of amiloride- sensitive sodium transport. The results are consistent with the interpretation that all chemosensitive areas may participate in the detection of salts but the degree of salt transport and the mechanism of transport is variable among different lingual epithelia and different species.      

Sparse spatial filter via a novel objective function minimization with smooth ℓ1 regularization

Common spatial pattern (CSP) method is widely used in brain machine interface (BMI) applications to extract features from the multichannel neural activity through a set of spatial projections. These spatial projections minimize the Rayleigh quotient (RQ) as the objective function, which is the variance ratio of the classes. The CSP method easily overfits the data when the number of training trials is not sufficiently large and it is sensitive to daily variation of multichannel electrode placement, which limits its applicability for everyday use in BMI systems. To overcome these problems, the amount of channels that is used in projections, should be limited to some adequate number. We introduce a spatially sparse projection (SSP) method that exploits the unconstrained minimization of a new objective function with approximated ?₁ penalty. Unlike the RQ, this new objective function depends on the magnitude of the sparse filter. The SSP method is employed to classify the multiclass ECoG and two class EEG data sets. We compared our results with a recently introduced sparse CSP solution based on ?₀ norm. Our method outperforms the standard CSP method and provides comparable results to ?₀ norm based solution and it is associated with less computational complexity. We also conducted several simulation studies on the effect of noisy channel and intersession variability on the performance of the CSP and sparse filters.     

The effects of boron-supplemented diets on adipogenesis-related gene expressions,anti-inflammatory,and antioxidative response in high-fat fed rats

The fatty liver syndrome caused by nutritional factors is a common cause of hepatic dysfunction globally. This research was designed to study the shielding effect of boron in rats fed a diet having high fat. Overall, 40 Wistar albino male rats were placed into one control and four treatment groups, that is, each having eight rats. Group I was provided with a standard rat diet while group II was only provided a high-fat diet for 60 days. Groups III, IV, and V were provided with 5, 10, and 20 mg/kg/day boron, respectively, by gastric gavage besides a high-fat diet for 60 days. Malondialdehyde was increased significantly in rats' blood and tissue because of high-fat diets. Glutathione was decreased significantly in blood and tissues because of a high-fat diet. Moreover, the activities of superoxide dismutase (SOD) and catalase (CAT) were decreased in the blood and tissues of the high-fat-fed rats. The genes expression for C-reactive protein, interleukin-1β, leptin, and tumor necrosis factor-α were increased while gene expression for peroxisome proliferator-activated receptors was decreased in the liver of rats fed with a high-fat diet. Contrariwise, boron supplementation improves antioxidative response in terms of increased SOD and CAT activities, gene expression regulation, and improved anti-inflammatory activities. In a nutshell, boron has dose-dependent shielding antioxidative and tissue regenerative effects in rats.     

The utilization of EMG biofeedback for the treatment of periorbital facial muscle tension

A case is presented of EMG feedback for reduction of tension in the orbicularis oculi muscle of both eyes. Feedback was provided for reduced firing of the upper and lower segments of the muscle. Within 25 sessions for the left eye and 20 sessions for the right, muscle output was markedly reduced from baseline and the patient reported no longer experiencing discomforting sensations of tightness. Follow-up of the patient 3 months posttreatment revealed that the initial problem of muscle tension no longer existed.The author is indebted to Charles H. Fitzpatrick, D.O., for his consultative services, to Augusta Alba, M.D., for her valuable critique and suggestions, and to John Mirone for his statistical services.     

Ratiometric intracellular calcium imaging in the isolated beating rat heart using indo-1 fluorescence.

Abnormalities in intracellular calcium (Ca(i)(2+)) handling have been implicated as the underlying mechanism in a large number of pathologies in the heart. Study into the relation between Ca(i)(2+) behavior and performance of the whole heart function could provide detailed information into the cellular basis of heart function. In this study we describe an optical ratio imaging setup and an analysis method for the beat-to-beat Ca(i)(2+) videofluorescence images of an indo-1 loaded, isolated Tyrode-perfused beating rat heart. The signal-to-noise ratio and the spatiotemporal resolution (with an optimum of 1 ms and 0.6 mm, respectively) made it possible to register different temporal Ca(i)(2+) transients together with left ventricle pressure changes. The Ca(i)(2+) transients showed that Ca(i)(2+) activation propagates horizontally from left to right during sinus rhythm or from the stimulus site during direct left ventricle stimulation. The indo-1 ratiometric video technique developed allows the imaging of ratio changes of Ca(i)(2+) with a high temporal (1 ms) and spatial (0.6 mm) resolution in the isolated Tyrode-perfused beating rat heart.     

Tissue and/or developmental stage specific methylation of nrDNA in Capsicum annuum

Journal of Plant Research - The nuclear ribosomal DNA (nrDNA) sequences are often used for phylogenetic analysis among organisms. Because DNA cytosine methylation and nucleolar dominancy are two...     

Noncontact dipole effects on channel permeation. III. Anomalous proton conductance effects in gramicidin

Proton transport on water wires, of interest for many problems in membrane biology, is analyzed in side-chain analogs of gramicidin A channels. In symmetrical 0.1 N HCl solutions, fluorination of channel Trp(11), Trp-(13), or Trp(15) side chains is found to inhibit proton transport, and replacement of one or more Trps with Phe enhances proton transport, the opposite of the effects on K(+) transport in lecithin bilayers. The current-voltage relations are superlinear, indicating that some membrane field-dependent process is rate limiting. The interfacial dipole effects are usually assumed to affect the rate of cation translocation across the channel. For proton conductance, however, water reorientation after proton translocation is anticipated to be rate limiting. We propose that the findings reported here are most readily interpreted as the result of dipole-dipole interactions between channel waters and polar side chains or lipid headgroups. In particular, if reorientation of the water column begins with the water nearest the channel exit, this hypothesis explains the negative impact of fluorination and the positive impact of headgroup dipole on proton conductance.