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Biomedical subjects

R L Miller

Publications and source records attributed to R L Miller.

At least 271 records · Page 15Linked to original sources
PubMed1977

Radioimmunoassay of atropine in plasma.

Antibodies, against atropine, were produced in rabbits immunized with atropine conjugated to bovine serum albumin. The antisera possessed a high binding affinity and were quite specific. The sensitivity of the method allowed detection of 6.25 ng of atropine per ml of plasma in a 10-microliter specimen. The method does not require an extraction procedure and can be performed using very small volumes of plasma. Plasma concentration-time profiles were determined by this method in dogs after rapid i.v. administration of atropine. Atropine declined from plasma in a biexponential fashion, exhibiting a terminal half-life of approximately 2.1 hours.

Animals↗
PubMed1976

Distinguishing cytomegalovirus, mycoplasma, and cellular DNA polymerases.

Cytomegalovirus-induced DNA polymerase can be distinguished from infected-cell enzymes by activity in 100 mM (NH4)2SO4. Virus polymerase is stimulated to 145% of control, whereas mock-infected cell polymerase is inhibited to 12% of control without added salt. Mycoplasmas induce a DNA polymerase in cell extracts that is stimulated to 130 to 180% by 25 mM (NH4)2SO4. Mycoplasma DNA polymerase may be mistaken for a virus-induced polymerase when virus stocks are contaminated. Identification of virus, cellular, and mycoplasma DNA polymerases in total cell extracts is described using sedimentation rate and effect of inhibitors on DNA polymerase activities.

Acetates↗
PubMed1976

Comparative ultrastructure of vallate, foliate and fungiform taste buds of golden Syrian hamster.

A fine-structure study of the hamster fungiform, foliate and vallate taste buds was undertaken for comparative purposes. All three taste bud types shared in common composition of the dark cells, light cells, basal cells, nerve fibers and nerve endings and undifferentiated peripheral cells, but morphological difference existed among them. The foliate and vallate taste buds were quite similar in their ultrastructural morphology. Their dark cells displayed long apical necks, long apical microvilli, apical osmiophilic secretory granules and an abundant rough endoplasmic reticulum. The dark cells of the fungiform taste buds, however, showed no neck formation and lacked apical osmiophilic granules. They had short apical microvilli and relatively scant rough endoplasmic reticulum. There was no difference in the fine structure features of the light cells, basal cells and neural elements of different types of taste buds. Both light and dark cells were much more readily distinguishable in foliate and vallate buds than in fungiform buds at both light-and electron-microscopic levels. Foliate and vallate buds demonstrated homogeneous dense substance within the taste pores while fungiform pores were frequently empty. It is speculated that the differences in taste bud morphology may be due to their different lingual locations and/or may be a reflection of the differences in the inductive influences from different nerves. Furthermore, structural differences may be responsible for varying thresholds to different taste modalities.

Animals↗
PubMed1976

An ultrastructural study on the development of vallate taste buds of the golden Syrian hamster.

An ultrastructural developmental study of hamster vallate taste buds was undertaken to demonstrate the sequential morphodifferentiation of their various cellular components. Under the neurogenic influence of the glossopharyngeal nerve, the undifferentiated epithelial cells of the vallate papilla first acquired fine structure features similar to those seen in the perigemmal adult peripheral cells and the gemmal basal cells. As the development progressed, the relatively undifferentiated basal cells appeared to differentiate into dark and light cell precursors. Mature light cells were frequently noted chronologically before any fully mature dark cells were observed. Transition from light to dark cells, or vice versa, was not noted at any time throughout the investigation, suggesting that light and dark cells originate as separate cell lines from the basal cells of the taste bud proper.

Age Factors↗
PubMed1976

A microsurgical technique for orthotopic ovarian transplantation in the Chinese hamster.

A microscopic surgical technique for the orthotopic transplantation of ovaries in the Chinese hamster is described. The procedure, which uses microcauterization of the mesovarian stump and closure of the ovarian bursa with microvascular suture, resulted in a 75 to 80 percent surgical success rate in a series of 12 nondiabetic and 12 diabetic hamsters. Applications include the production of prediabetic offspring, the study of intrauterine environmental effects on transplant-derived offspring, and the preservation of endangered genetic colony sublines.

Animals↗
PubMed1975

A study of protein-sodium dodecyl sulfate complexes by transient electric birefringence.

The method of transient electric birefringence has been applied to study the conformation of protein-sodium dodecyl sulfate complexes. A model of a deformable prolate ellipsoid has been proposed for the protein-dodecyl sulfate complex. This model is compared to the models proposed by J. A. Reynolds and C. Tanford (1970), J. Biol. Chem. 245, 5161) and K. Shirahama, K. Tsujii, and T. Takagi (1974, J. Biochem. 75, 309). Differences between these latter two models are resolved by the model presented here. In addition, it has been demonstrated that protein molecular weights may be obtained from the slow relaxation time for transient electric birefringence of protein-dodecyl sulfate complexes.

Animals↗
PubMed1975

Interaction of leukocytes and endotoxin with the plasmin and kinin systems.

Leukocytes can generate a substance that, when added to some partially purified human kininogen, is capable of forming kinins. The addition of endotoxin or polystyrene latex particles to the incubated leukocytes doubled the amount of kinin generated. Certain preparations of kininogen, however, failed to allow kinin formation by the leukocytes. No evidence could be found that an activator of prekallikrein or a kallikrein was present in the granulocyte preparations. However, the addition of highly purified plasminogen to inactive kininogen preparations restored their ability to generate kinins in the presence of leukocytes. All the kininogen preparations that allowed kinin formation when incubated with leukocytes contained plasminogen. These data suggest that a plasminogen activator is present on the leukocyte surface. This activator activates plasminogen to form plasmin which in turn acts on kininogen to release a kinin and thus provides a mechanism for the formation of kinins in inflammatory exudates and during endotoxemia.

Endotoxins↗
PubMed1975

Attribution versus persuasion as a means for modifying behavior.

The present research compared the relative effectiveness of an attribution strategy with a persuasion strategy in changing behavior. Study 1 attempted to teach fifth graders not to litter and to clean up after others. An attribution group was repeatedly told that they were neat and tidy people, a persuasion group was repeatedly told that they should be neat and tidy, and a control group received no treatment. Attribution proved considerably more effective in modifying behavior. Study 2 tried to discover whether similar effects would hold for a more central aspect of school performance, math achievement and self-esteem, and whether an attribution of ability would be as effective as an attribution of motivation. Repeatedly attributing to second graders either the ability or the motivation to do well in math proved more effective than comparable persuasion or no-treatment control groups, although a group receiving straight reinforcement for math problem-solving behavior also did well. It is suggested that persuasion often suffers because it involves a negative attribution (a person should be what he is not), while attribution generally gains because it disguises persuasive intent.

Achievement↗
PubMed1975

Chemotactic ability of dental plaque upon autologous or heterologous human polymorphonuclear leukocytes.

The chemotactic effect of pooled human plaque suspension, supernatant, and ultrafiltrate upon heterologous human PMNs was investigated using the Boyden chamber technique. It was observed that pooled plaque suspensions (20 mg/ml) were consistently chemotactic for heterologous human PMN cells. Whole plaque suspensions were most chemotactic, and the supernatant was approximately half as active, while the bacteria-free ultrafiltrate induced a negligible chemotactic response. Chemotactic assays of individual plaque suspensions were also performed. Twelve male subjects were paired according to age and PDI scores to assess whether the PMN cells of certain individuals responded differently to their autologous plaque. When comparing subjects with high or low PDI scores, there were no significant differences in the chemotactic responses. However, a trend of reduced chemotaxis was observed in most subjects with a high PDI. When the subjects were arbitrarily divided into groups with high and low plaque indices, a greater overall chemotactic response was generated by the higher plaque formers. The differences between the two groups, however, were not statistically significant.

Adult↗