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PubMedDate not supplied

Comparison of two dissolution apparatuses with correlation of in vitro-in vivo data for prednisone and prednisolone tablets.

Dissolution profiles in 0.1N hydrochloric acid using both the paddle stirrer apparatus and the spin filter apparatus were obtained for prednisone tablets made by seven different manufacturers and prednisolone tablets made by eight different manufacturers. Dissolution parameters were correlated with results obtained in three human bioavailability trials which were previously reported. Also, results obtained in one apparatus were correlated with those obtained in the other apparatus. Such correlations may be useful in the setting of in vitro dissolution rate specifications for commerical prednisone and prednisolone tablets.

Biological Availability↗
PubMed2006

Development of the tentacular apparatus in sipunculans (Sipuncula): I. Thysanocardia nigra (Ikeda, 1904) and Themiste pyroides (Chamberlin, 1920).

The development and arrangement of the tentacular apparatus of Thysanocardia nigra (Ikeda, 1904) and Themiste pyroides (Chamberlin, 1920) are described and illustrated using scanning electron microscopy. In T. nigra, the tentacular apparatus is composed of two crowns: the nuchal arc enclosing the nuchal organ and a crown of numerous oral tentacles arranged in U-shaped festoons. In early juveniles, two dorsal horn-like protrusions develop into the first, or primary, pair of tentacles of the nuchal arc. The second pair of tentacles of the nuchal arc develops dorsolaterally on the bases of the primary tentacles. Two ventrolateral lobes of the oral disk grow and become subdivided by the longitudinal ciliary groove into anlages of one set of dorsal and one set of ventral tentacles, thus forming a first oral festoon. Later, a pair of dorsolateral lobes develop between the first festoons and the nuchal arc to form a second pair of oral festoons. The third and following pairs of oral festoons develop in the dorsolateral growth zones lateral to the borders of the nuchal arc, where they meet the oral crown. The growing festoons extend down the oral disk and run alongside the head. A new oral tentacle appears directly at/on the base of the previous tentacle, thus giving rise to a typical sympodium with an alternating arrangement of tentacles. In T. pyroides, a second pair of tentacles develops from two ciliary lobes that are ventrolateral outgrowths of the circumoral ciliary field around the terminal mouth opening. The third pair of tentacles appears from the dorsolateral lobes at the base of primary tentacles, between the first two pairs of tentacles. These six tentacles determine the position of six main stems of the tentacular apparatus designated the first tentacles in the corresponding stems. The second tentacle in every stem appears as a ventrolateral outgrowth at the base of the first tentacle. The third and following tentacles in the stem are developed between the two previous tentacles according to a sympodial pattern. In both species, the distinct sympodial pattern in the arrangement of tentacles in the tentacular apparatus is well evidenced by the outlines of the ciliary oral grooves. The branched stems of T. pyroides may be homologized structurally and functionally to the oral festoons of T. nigra. J. Morphol. (c) 2006 Wiley-Liss, Inc.

Animal Structures↗
PubMed2003

Development and validation of a 96-well equilibrium dialysis apparatus for measuring plasma protein binding.

A 96-well equilibrium dialysis block was designed and constructed that is compatible with most standard 96-well format laboratory supplies and instruments. The unique design of the dialysis apparatus allows one to dispense and aspirate from either or both the sample and dialysate sides from the top of the apparatus, which is not possible with systems currently on the market. This feature permits the investigator to analyze a large number of samples, time points, or replicates in the same experiment. The novel alignment of the dialysis membrane vertically in the well maximizes the surface-to-volume ratio, eliminates problems associated with trapped air pockets, and allows one to add or remove samples independently or all at once. Furthermore, the design of the apparatus allows both the sample and dialysate sides of the dialysis well to be accessible by robotic systems, so assays can be readily automated. Teflon construction is used to minimize nonspecific binding of test samples to the apparatus. The device is reusable, easily assembled, and can be shaken in controlled temperature environments to decrease the time required to reach equilibrium as well as facilitate dissolution of test compounds. Plasma protein binding values obtained for 10 diverse compounds using standard dialysis equipment and the 96-well dialysis block validates this method.

Blood Proteins↗
PubMed2001

Development of Automatic Adsorption Apparatus for Binary Mixture: Measurement of Individual Adsorption Isotherms of Ethanol and Water from Their Mixed Vapors by Active Carbon Fiber.

The automatic adsorption apparatus has been developed to measure the individual adsorption isotherms of constituent vapor from binary mixed vapor. The present adsorption apparatus consists of a combination of gravimetry and volumetry. The weight increase due to gas adsorption was determined by the magnetic suspension vacuum balance with a sensitivity of 0.01 mg, while the pressure decrease due to adsorption was measured by a high precision pressure gauge with a sensitivity of 0.2 Pa. The adsorption data obtained from both gravimetry and volumetry make it possible to determine the individual isotherms of the constituent vapors without chemical analysis, if the molecular weights of the constituent vapors are significantly different one another. In the later part of this work, the present adsorption apparatus has been applied to measure the individual adsorption isotherms of ethanol and water by active carbon fiber from their mixed vapor. The reliability of the individual isotherms measured by the present apparatus has been considered. The adsorption data obtained in the present work clearly indicate that ethanol molecules are preferentially adsorbed into the micropores of active carbon fiber with a pore width of 0.67 nm. The present adsorption result suggests the possibility of the energy-saving separation of ethanol from the mixed vapors of ethanol and water. Copyright 2001 Academic Press.

Journal Article↗
PubMed1997

gamma-AChR/epsilon-AChR switch at agrin-induced postsynaptic-like apparatus in skeletal muscle.

We transfected the extrajunctional region of denervated soleus muscles in adult rats with neural agrin cDNA to induce myofibers to form postsynaptic-like apparatus containing acetylcholine receptor (AChR) aggregates. By 1 week approximately 30% of the AChR aggregates contained a mixture of epsilon-AChRs and gamma-AChRs while approximately 70% had only gamma-AChRs. If the transfected muscles were reinnervated in the original junctional region, the postsynaptic-like apparatus, despite the absence of apposed axon terminals, gradually came to have only epsilon-AChRs. We conclude that at the postsynaptic apparatus of ectopic neuromuscular junctions formed by a foreign nerve implanted into the extra-junctional region of denervated muscles, agrin secreted by the axon terminal plays a direct role in the gamma-AChR/epsilon-AChR switch that occurs as the apparatus reaches maturity. Our findings, together with results from other studies, indicate further that agrin and acetylcholine are the only nerve-derived factors required for this switch.

Agrin↗
PubMed1998

Neuregulins and erbB receptors at neuromuscular junctions and at agrin-induced postsynaptic-like apparatus in skeletal muscle.

We demonstrate by immunohistochemistry that at least two isoforms of neuregulin (NRG) are concentrated at neuromuscular junctions in adult rat muscles. One is NRGbeta3, a secreted protein which is bound to basal lamina that occupies the synaptic cleft. The other(s), NRG-a, is in the muscle fibers' plasma membrane. We show further that muscle NRG, including NRG-a, is concentrated at postsynaptic-like apparatus induced to form in the extrajunctional region of the soleus muscle by exposure to neural agrin. The agrin-induced postsynaptic-like apparatus also includes aggregates of the NRG receptors erbB2 and erbB3 as does postsynaptic apparatus at neuromuscular junctions. These findings together with those of others suggest a mechanism by which neural agrin induces the expression of epsilon-AChR subunits in postsynaptic-like apparatus, and they support the hypothesis that agrin has a similar function at neuromuscular junctions.

Agrin↗
PubMed2001

Apparatus for the quantitative analysis of the aroma of french bread and its loss during storage.

Based on the principles of static and dynamic headspace sampling, an apparatus was developed for the determination of the release of potent odorants from two types of baguette (industrial process or "intensifée" and traditional or "artisanal") differing in their odor profiles. We applied this apparatus to get an insight into the aroma changes of freshly baked French bread, which develops a stale off-flavor within four hours after baking. Model mixtures containing the odorants in the concentrations found by the headspace analysis were evaluated using the apparatus as an olfactometer. By comparing the odor profiles of the models with those of the baguettes, the quantitative data were confirmed. The results indicate that losses of methylpropanal, 2- and 3-methylbutanal and, on the other hand, an increase of hexanal and (E)-2-nonenal led to a stale off-flavor. Furthermore it was suggested that this apparatus is also suitable for precise flavor release studies of other foods.

Bread↗
PubMed1976

An apparatus and a method for measuring the relationship of triceps surae torques to tibio-tarsal angles in man.

1. The apparatus and method described give the relationship of triceps surae torque to the absolute tibio-tarsal angle. Data of the anatomy of the foot and the axis of the ankle are taken into consideration. They make complementary measurements necessary, which in certain cases enable the angle recorded by the apparatus to be corrected so as to obtain the true angle. 2. The reliability of the apparatus and the technique of linkage of subject to apparatus are judged by examination of the torque-angle plots obtained by passive stretching of the triceps in 7 subjects for whom correction is monor. Good reliability was observed during the session and from one session to another. The plot is exponential. The merits of the method of correcting angles are illustrated in three subjects with the same protocol: when plots are not corrected, they are more dispersed during the session and no longer exponential. These results justify the considerable correction of the angle that we propose in the study of isometric contractions.

Adult↗
PubMed1999

The protein-import apparatus of plant mitochondria.

The import and assembly of mitochondrial proteins synthesized in the cytosol is mediated by the protein-import apparatus which plays a central role in mitochondrial biogenesis. Ten years ago only some components of the protein-import apparatus from fungi and mammals were characterized, but today its major components have been analyzed at the molecular level also in plants. Interestingly there are specific features which distinguish the protein-import apparatus of plants from that of fungi and mammals. Here we give an overview of all known components of the protein-import apparatus from plants and focus on its differences in comparison to heterotrophic eukaryotes.

Animals↗
PubMed1997

Formation of a whorl-like autophagosome by Golgi apparatus engulfing a ribosome-containing vacuole in corpora allata of the cockroach Diploptera punctata.

Previously, we showed that synchronous autophagy occurred in the corpora allata during the declining phase of juvenile hormone synthesis in mated adult females of the cockroach Diploptera punctata. At the onset of this process, conspicuous whorl-like autophagosomes were often observed. Each consisted of a ribosome-containing vacuole at the center surrounded by about eight layers of double membranes. Labeling the cis-Golgi cisternae with hot osmium and histochemical detection of thiamine pyrophosphatase in the trans-Golgi cisternae were used to trace the autophagic process. We conclude that the membranes surrounding the whorl-like autophagosome are derived from the entire Golgi apparatus with its cis-cisternae forming the outermost layer and the trans-cisternae the innermost layer. The engulfing process is initiated through direct contact between trans-cisternae of the Golgi apparatus and the isolation membrane of the ribosome-containing vacuole. Formation of a whorl-like autophagosome appears to be a highly regulated process specific to ribosome-containing vacuoles since it occurs only on day 5 and the Golgi apparatus does not recognize membranes of other types of autophagic vesicles or of functional organelles. This novel behavior of the Golgi apparatus in the corpora allata should play an important role in the long-term inhibition of juvenile hormone synthesis (e.g., during gestation) since it results in the depletion of cellular machinery for juvenile hormone synthesis.

Journal Article↗
PubMed1983

A versatile apparatus for electrophoresis including isoelectrofocusing and its performances.

A new versatile electrophoresis apparatus with a circulating cooling plate for analytical, preparative, and two-dimensional electrophoresis, including isoelectrofocusing, was designed and constructed. The apparatus consists of six main separable blocks and two removable bar electrodes. Each block in the apparatus usually has more than two roles and can easily be assembled with paper clips. Various combinations of the blocks and electrodes enable one to assemble not only an apparatus for horizontal (flat-bed), vertical slab, disc gel, and preparative electrophoresis, but also preparative isoelectrofocusing.

Autoanalysis↗
PubMed1986

High resolution preparative gel electrophoresis of DNA fragments and plasmid DNA using a continuous elution apparatus.

An apparatus designed for preparative gel electrophoretic separation of proteins (M. A. Hediger, (1984) Anal. Biochem. 142, 445-454) has been used successfully for separating DNA restriction fragments. The apparatus displayed yields and resolutions that are higher than those obtainable with commercially available devices. The amounts of DNA applied to the column range from a few micrograms to milligram quantities. Restriction DNA fragments very similar in size were isolated in pure form with the apparatus. After ethanol precipitation, these fragments were successfully used for restriction enzyme cleavages, ligation, or chemical sequencing. Furthermore the apparatus provides a convenient method for the large-scale isolation of plasmid DNA. The method requires only 4 h of electrophoresis and therefore greatly reduces the preparation time compared with the conventional equilibrium centrifugation method which requires centrifugation times of up to 60 h. In contrast to the centrifugation method, contaminants such as RNA, proteins, and chromosomal DNA are efficiently removed by this technique.

DNA↗
PubMed1992

A new co-culture method utilizing a dual compartment cell-allocation apparatus for observation and identification of synapse formation in vitro.

A new co-culture method for observation and identification of synapse formation utilizing dissociated retinal and tectal neurons from 7-day-old chick embryos was developed using a glass apparatus which we named 'Dual Compartment Cell-Allocation Apparatus.' This apparatus enabled us to culture these two types of cells by forming two parallel lanes, each with a dimension of 200 microns by 15 mm and with an interval of 200 microns separating the two lanes, on a collagen-coated cover slip. Infiltration and/or migration of retinal cells into the tectal cell lane was minimal with only 0.15% identified and confirmed with the fluorescence-dye labeling method. Growth of neurites connecting the two lanes was observed within 48 h of culture in a serum-free medium. Double-immunostaining of the culture preparations with anti-neurofilament and anti-synaptophysin antibodies revealed the presence of synaptophysin-hot spots on neurofilament-positive processes connecting the retinal neurons with the tectal neurons, thus confirming the formation of synapses between the neurons of the retinal lane and the neurons of the tectal lane. The dual compartment cell-allocation apparatus has proven itself to be advantageous and useful for studying the formation of synapses between two types of neurons from different origin.

Animals↗
PubMed1986

An improved perfusion apparatus for small animal hearts.

A perfusion apparatus for mechanical and electrophysiological studies in small animal (e.g., rat, guinea pig) hearts is described. The apparatus consists of a number of individual perfusion chambers connected to the aortic perfusion cannula of a Langendorff perfused heart. The aortic root perfusion pressure is controlled by the oxygenating gas (usually 5% CO2 in O2) at a range of 0-200 mmHg. Different solutions can be placed in different individual chambers. Pressure in the left ventricle is monitored by means of a special compliant, but nonelastic, balloon while special atraumatic electrodes allow high-voltage, noise-free ECG recordings to be made from all parts of the epicardium. The apparatus keeps hearts beating for hours while the multichamber allows multiple drug applications to be made rapidly. Thus, the apparatus can be used for all types of pharmacodynamic analysis.

Animals↗
PubMed1982

An observation chamber for a high-pressure stopped-flow apparatus.

A new design of the observation window to observation chamber seal is described for the Berger rapid stopped-flow apparatus. This design permits reliable operation of the apparatus and retains the features of a square non-deviating observation path with flush windows. Incorporation of fiber optic light guides for the observation path has made the apparatus insensitive to vibration artifacts. A demonstration reaction of calcium binding to EGTA is presented; the reaction, which is 90% complete within 2 ms, illustrates the capability of this apparatus for examining fast reactions.

Biochemistry↗
PubMed1984

Electroblotting of multiple gels: a simple apparatus without buffer tank for rapid transfer of proteins from polyacrylamide to nitrocellulose.

A simple, horizontal device for rapid electrophoretic transfer of proteins from several polyacrylamide gels simultaneously is described. Up to six 'TRANS-UNITS' consisting of soaked filter paper on either side of polyacrylamide gel/nitrocellulose sheets that are separated by dialysis membranes are stacked between graphite plate electrodes. The only buffer reservoir in the apparatus is that in stacked, soaked filter paper. A special buffer system based on the isotachophoresis theory was developed for this purpose. The electrophoretic transfer was performed with equal efficiency in all TRANS-UNITS of the stack. Only traces of a few proteins remained in the polyacrylamide gel after transfer. With this apparatus, 50 protein bands from a human serum protein sample (diluted 1 : 100) were detected by immunoblotting with the retainment of the high resolution of the SDS-PAGE technique. The apparatus provided a constant current density of 0.8 mA/cm2 during the 1-h transfer time at 21 degrees C, irrespective of the number of TRANS-UNITS. The apparatus generated 1-5 W in joule heat, depending on the number of TRANS-UNITS in the stack.

Blood Protein Electrophoresis↗
PubMed1984

A polychromatic flash photolysis apparatus (PFPA).

A wide variety of biologically relevant chemical intermediates have been identified and characterised by their spectral properties. When rapid kinetics, i.e. rapid changes in these spectral properties are studied, the equipment designed for these studies (flash photolysis-, T-jump apparatus) usually allows only the registration of intensity changes of the monitoring light beam at one particular wavelength. Quite frequently, however, particularly in biological systems, the reactions of interest are too complex to be fully understood using single wavelength techniques. We have therefore designed and built a flash photolysis apparatus which permits the simultaneous recording of absorbance changes at 32 wavelengths, freely selectable between 300 and 1000 nm, as well as changes in fluorescence, luminescence, birefringence and light scattering. The apparatus, which we have called Polychromatic Flash Photolysis Apparatus (PFPA), acquires up to 8000 difference spectra per second with an amplitude resolution of better than 0.0001 absorbance unit. Data acquisition and activation of an actinic xenon flash unit occurs under computer control. The same computer is responsible for data storage, handling and graphic display. This communication describes the PFPA, its performance, and, as a demonstration of its potential usefulness, its application to the measurement of the light driven photocycle of bacterial rhodopsin, the proton pumping protein of Halobacterium halobium.

Photolysis↗
PubMed1995

A spring-activated tilting apparatus for the study of balance control in man.

A tilting apparatus has been designed and constructed to produce fore-aft whole head-and-body tilt (WHBT) alone, or in combination with ankle dorsiflexion of standing subjects, about an axis colinear with the ankle joint. The apparatus is composed of a vertical tilting structure attached to a supporting base. Mechanical rotation of the vertical tilting structure is achieved by a spring activating system mounted on its base. Subjects are secured to the vertical structure by a body harness system with the head fixed, and the feet secured to the standing platform. Simultaneous dynamic WHBT and ankle joint displacement are induced by rotating the vertical support; whereas WHBT alone is achieved by concurrent rotation of both the vertical support and standing platform. Tilts are triggered manually, and data acquisition precedes head acceleration onset by 50-100 ms to provide suitable baseline values. This tilting apparatus has been successfully used to apply forward WHBT in 34 subjects with height ranging from 1.55 to 1.87 m and weights from 42 to 95 kg, and at magnitudes of peak head acceleration varying from 0.4 to 2.2 g as measured by a linear accelerometer mounted on a dental bite. These acceleration rates can be reproduced with minor variation in the same subjects. Moreover, the area under the head acceleration traces was reproducible within 15% between subjects. Tilts can be delivered with concomitant ankle dorsiflexion. These features make the low-cost tilting apparatus a very useful tool for the study of human tilting reactions in both laboratories and clinical settings.

Acceleration↗