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PubMed1987

Enzymatic histochemistry of mouse kidney in plastic.

Two-micrometer sections of methacrylate-embedded kidney were used to investigate the enzymatic activities of mouse kidney where the proximal tubule and Bowman's capsule from the same corpuscle were viewed in the same section. Alkaline phosphatase, acid phosphatase, 5'-nucleotidase, gamma-glutamyl transpeptidase, N-acetyl-beta-glucosaminidase, leucine aminopeptidase, alpha-naphthyl butyrate esterase, and adenosine triphosphatase activities were observed in the proximal tubule, but only 5'-nucleotidase, alpha-naphthyl butyrate esterase, and alkaline phosphatase were observed in the squamous portion of the parietal epithelium of Bowman's capsule. The use of methacrylate-embedded tissue allowed more precise localization of enzymatic activity than is possible with most frozen sections. This may provide interesting applications not only for characterization of kidney diseases but also for characterization of other normal and abnormal tissues.

5'-Nucleotidase↗
PubMed2005

Method for embedding optical fibers in an aluminum matrix by ultrasonic consolidation.

The overall aim of the research, part of which is outlined in this paper, was to utilize the ultrasonic consolidation (UC) process for the fabrication of smart metal structures, capable of measuring an external stimulus and responding to this stimulus by adapting its structure accordingly through embedding both active and passive functional elements. This paper presents a fundamental study of embedding methods for the fabrication of optical fibers embedded within aluminum structures. The methods considered in this paper produced embedded optical fiber specimens in which large amounts of plastic flow were observed within the matrix. The matrix material deformed around the fibers, resulting in fully embedded optical fibers capable of transmitting a bright light source and without damaging the fibers. Based on light responses, a general process window was drawn to show the range at which optical fibers can be embedded within aluminum structures using the UC process. The outcomes lay down initial investigative principles for the further development of the technology for embedding or cladding of optical fiber sensors, such as fiber Bragg grating devices, within or on metal structures: for example, the cladding of large free-form metal structures or smart "skinned" metal foam or metal honeycomb structures.

Journal Article↗
PubMed1994

Glycol methacrylate embedding and microwave staining for light microscopy of the mouse cochlea.

This study examined the utility of a methacrylate-based embedding medium and microwave staining for light microscopic quantification of hair cells and spiral ganglion cells in the mouse cochlea. The most important phase of the preparation process involved slowing down the polymerization process. The tissue molecules so locked within the plastic matrix produced excellent preservation of the organ of Corti and adjacent structures including the spiral ganglion, as well as tissue ionic charges. Excitable by microwaves, these ionic charges accelerated the movement of the basic dye (hematoxylin) into the tissue, reducing the time for this segment of the staining process from approximately 45 minutes to 1-2 minutes. When embedded in glycol methacrylate (GMA), acidic dyes show less stain-cell affinity so that staining intensity and time cannot be improved significantly. However, addition of color extenders to the counterstain eosin produced distinguished staining of all tissue constituents. Thus, a combination of GMA embedding medium, use of the microwave for staining and addition of color extenders to the counterstain generated excellent structural resolution and contrast. This made both hair cell and spiral ganglion cell counts possible from within the same specimen and provided an opportunity for qualitative evaluation as well.

Animals↗
PubMed1989

Immunocytochemical localization of glutamate immunoreactivity in the guinea pig cochlea.

The localization of glutamate immunoreactivity was examined in the guinea pig cochlea using affinity purified polyclonal antibodies to glutamate and immunoperoxidase post-embedding staining techniques on one micron plastic sections. Glutamate immunoreactive staining was seen in both inner and outer hair cells and in spiral ganglion cells and auditory nerve fibers. These results support the hypothesis that glutamate may function as the hair cell transmitter or as a precursor to the transmitter and add further support for an excitatory amino acid as the transmitter of the auditory nerve.

Animals↗
PubMed2026

Cells and Networks in Flux: Rethinking Ontogenesis and Pathogenesis.

Organ and tissue functions emerge from the coordinated activity of cell networks. Therapeutics that act on pathogenic cell networks, modulating their cellular interplay, follow naturally. Over several decades, our laboratory has developed a series of approaches for rewiring cell networks, culminating in a class of cell surface-directed signal converter proteins (SCPs) that do so by modulating juxtacrine and autocrine signaling in and among their nodal cells. A first such SCP has now produced encouraging clinical data for cancer immunotherapy. Yet, these early network-directed fusion proteins rest on a deliberately simplified picture: discrete end-cell types plugged into graphically tractable networks. That picture is increasingly at odds with what computational cell typing and spatiotemporal analytics, along with epigenetics, now reveal-a hyperdiverse, plastic, experience-shaped cellular landscape embedded in dynamic, multiway networks. Setting the stage for a next generation of network modulators, an extended cell differentiation synthesis is proposed, which formalizes paracell ultradifferentiation and aging-associated differentiation phases. According to this model, cells are ever evolving, and no two cells are alike. A richer cellular ontology forces a more elaborate network ontology, with paralogous networks and their shifting subnetworks opening a concrete design space for next-generation network-directed SCP therapeutics. This exploration calls for a willingness to embrace complexity more fully and borrow freely from conceptual fields close and afar.

Humans↗
PubMed1991

An automated method for DNA preparation from thousands of YAC clones.

We describe an automated method for the preparation of yeast genomic DNA capable of preparing thousands of DNAs in parallel from a YAC library. Briefly, the protocol involves four steps: (1) Yeast clones are grown in the wells of 96-well microtiter plates with filter (rather than plastic) well-bottoms, which are embedded in solid growth media; (2) These yeast cultures are resuspended and their concentrations determined by optical density measurement; (3) Equal numbers of cells from each well are embedded in low-melting temperature agarose blocks in fresh 96-well plates, again with filter bottoms; and (4) DNA is prepared in the agarose blocks by a protocol similar to that used for preparing DNA for pulsed-field gels, with the reagents being dialyzed through the (filter) bottoms of the microtiter plate. The DNA produced by this method is suitable for pulsed-field gel electrophoresis, for restriction enzyme digestion, and for the polymerase chain reaction (PCR). Using this protocol, we produced 3000 YAC strain DNAs in three weeks. This automated procedure should be extremely useful in many genomic mapping projects.

Blotting, Southern↗
PubMed2005

Ultrafast intrachain photoexcitation of polymeric semiconductors.

We report on excited state dynamics in isolated poly(9,9-dioctylfluorene) chains obtained by embedding the polymer in an inert plastic matrix. Early events (<300 fs) of intrachain photophysics are detected by pump-probe spectroscopy using tunable UV 25-fs pump pulses and sub-10-fs visible probe pulses. We show that higher-lying optical states, reached by multiphoton transitions, give rise to on-chain charge separation on the ultrafast time scale. The intrachain charge pair decays geminately within 500 fs to the lowest singlet state. Characteristic time scales for internal conversion and intramolecular vibrational redistribution are also determined.

Journal Article↗
PubMedDate not supplied

The development of improved ultrasound heaters suitable for superficial tissue heating.

The acoustical fields generated by several ultrasound heaters have been measured to determine their suitability for heating superficial lesions in cancer patients. Three different acoustical sensors were used in the study, and one sensor, consisting of a thermocouple embedded in a sound-absorbing plastic, proved to be the most practical device for routine use. The method employed to mount the piezoelectric crystal in the heater was found to have a profound effect on the acoustical field generated by the heater. Clamping the crystal close to its edge resulted in a field with a prominent acoustical maxima on the crystal axis. A flexible attachment at the very edge of the crystal resulted in a much more uniform field which could be further improved by rapidly sweeping the frequency of the signal used to excite the piezoelectric crystal. A heater in which the rear electrode of the piezoelectric crystal is sectioned into a series of concentric rings has also been developed. This heater can deposit more acoustical energy at the edges of a treatment volume than at the center, and the diameter of the ultrasound beam can also be adjusted. The results demonstrate that (i) the acoustical fields of ultrasound heaters must be accurately measured before using the heaters clinically, and that (ii) by careful design, both uniform or controlled nonuniform acoustical fields can be generated.

Hot Temperature↗
PubMed1973

Demonstration of ribosomes in mesosomes associated with Bacillus subtilis protoplasts.

The physiological differences between Bacillus subtilis (ATCC 6633) cells derived from a glucose-salts-yeast extract (GSY) medium and those of cells from tryptose broth permitted the identification of variables in protoplasting environments which noticeably affected the clarity of mesosomal ribosomes. They were the sucrose and magnesium ion concentrations and the type of buffer used. The environment suitable for conversion of GSY cells to the protoplast state was a 0.02 M tris(hydroxymethyl)aminomethane-hydrochloride buffer, pH 7.2, containing 0.6 M sucrose and 0.03 M MgCl(2). Branched mesosomal tubules and a unique organization of vesicles were detected in thin sections and in negative stains of the specimens. Ribosomes were demonstrable in the extruded structures associated with protoplasts that had been prepared according to four fixation schedules and embedded in either of two epoxy plastics. Adjustments in the fixation schedules improved the clarity of the large bodies of protoplast cytoplasm to a degree equivalent to that of their dangling appendages.

Bacillus subtilis↗
PubMed2004

Soil reinforcement with recycled carpet wastes.

A root or fibre-reinforced soil behaves as a composite material in which fibres of relatively high tensile strength are embedded in a matrix of relatively plastic soil. Shear stresses in the soil mobilize tensile resistance in the fibres, which in turn impart greater strength to the soil. A research project has been undertaken to study the influence of synthetic fibrous materials for improving the strength characteristics of a fine sandy soil. One of the main objectives of the project is to explore the conversion of fibrous carpet waste into a value-added product for soil reinforcement. Drained triaxial tests were conducted on specimens, which were prepared in a cylindrical mould and compacted at their optimum water contents. The main test variables included the aspect ratio and the weight percentage of the fibrous strips. The results clearly show that fibrous inclusions derived from carpet wastes improve the shear strength of silty sands. A model developed to simulate the effect of the fibrous inclusions accurately predicts the influence of strip content, aspect ratio and confining pressure on the shear strength of reinforced sand.

Compressive Strength↗
PubMed1980

Embedment in glycol methacrylate at low temperature allows immunofluorescent localization of a labile tissue protein.

The antigenic activity of a labile protein postulated to the hormone ovine chorionic somatomammotropin (OcS) is preserved in tissue fixed in either glutaraldehyde or paraformaldehyde and low temperature-embedded in the water-soluble plastic glycol methacrylate. Immunofluorescence techniques used on 1--2 micrometer thick sections show that this protein is located in the cytoplasm of certain fetal chorionic cells in association with small spherical bodies, which may be lipid. The use of borohydrate reduction or treatment with Schiff's reagent to reduce glutaraldehyde-induced background fluorescence is described.

Animals↗
PubMed1982

Immunocytochemical identification of dye-injected cells.

Lucifer Yellow CH may be injected into pancreatic islet cells and visualized in Epon sections of the embedded tissue both before and after plastic removal and immunocyto-chemical staining. The dye retains its fluorescence, clearly marking the injected cell and adjacent dye-coupled cells, but does not interfere with the indirect immunofluorescent staining patterns that are characteristic of the islet cells

Animals↗
PubMed1990

Healthcare provides many opportunities for card technologies.

Smart cards and optical memory cards are among the fastest growing technologies today. Though their use in healthcare is not yet widespread, they promise great potential benefits in several areas of healthcare delivery. Both cards are credit card-sized plastic devices that can store information. Embedded in smart cards are one or more computer chips which store and process information, and some cards provide as much computer power as a PC. Optical memory cards use laser technology to store and read information.

Europe↗
PubMed1978

A 2 hand phantom.

A technique for embedding hand and wrist bones in plastic resin is described.

Costs and Cost Analysis↗
PubMed1978

Serial sacrifice study of pathogenesis of 210Po-induced lung tumors in Syrian golden hamsters.

The pathogenesis of 210Po-induced tumors in the peripheral lung of Syrian golden hamsters has been studied in a serial sacrifice experiment utilizing both plastic (glycol methacrylate) and routine paraffin embedding procedures for lung sections. A rapid progression from hyperplasia of bronchiolar-type cells that appear in the alveolar region to malignant tumors was documented. Tumors began appearing as early as 15 weeks after the first intratracheal instillation of 210Po.

Adenocarcinoma↗
PubMed1989

Synaptic plasticity and learning. II: Do different kinds of plasticity underlie different kinds of learning?

This paper discusses certain issues connected with the question of whether synaptic plasticity is involved in information storage by the brain. We begin by contrasting two well documented types of synaptic plasticity--activity-dependent modulation of presynaptic facilitation ("Kandel synapses") and NMDA receptor triggered alterations in excitatory amino acid transmission ("Hebb synapses"). We then propose that, embedded-into appropriate circuitry, these different forms of plasticity might underlie different kinds of learning. In partial support of this idea, we show that, in freely moving rats, intrahippocampal microinfusion of the NMDA-receptor antagonist D,L-AP5 causes a dose-dependent impairment of a type of spatial learning known to be sensitive to disruption by hippocampal lesions (water-maze place-navigation). In a second experiment, the same drug infusion protocol is shown to cause a blockade of hippocampal long-term potentiation in vivo across a comparable dose range. Finally, third, autoradiographic experiments indicate that diffusion of the drug was largely restricted to the hippocampus. Together, these results (1) suggest that blockade of hippocampal NMDA receptors, under conditions which leave baseline synaptic transmission relatively unaffected, blocks a type of learning with which the vertebrate hippocampus has been implicated on the basis of neuropsychological work; and (2) supports Abrams and Kandel's Trends Neurosci. 11 (1988) recent proposal that there may be several logically distinct forms of synaptic plasticity.

Animals↗
PubMed2000

A practical technique to postfix nanogold-immunolabeled specimens with osmium and to embed them in Epon for electron microscopy.

Nanogold is a tiny gold probe, freely diffusible in cells and tissues, and is suitable for pre-embedding immunohistochemistry. However, it is necessary to develop Nanogold to a larger size so that it can be observed by conventional transmission electron microscopy. Silver enhancement is usually used for visualizing Nanogold, but the silver shell produced is unstable in OsO(4) and often becomes invisible after OsO(4) postfixation, which is necessary for good visualization of ultrastructure. We used silver enhancement with silver acetate, followed by gold toning with chloroauric acid, to replace the silver shell with a more stable gold in order to observe Nanogold after osmium fixation and Epon embedding. This technique is applicable to various intra- and extracellular antigens. For correlative observation of immunolabled specimens by light and electron microscopy, specimens adhered to slideglasses were embedded in Epon under non-adhesive plastic film. By heating the Epon sheets after polymerization, these supports were removed without difficulty and provided easy correlative observation.

Animals↗