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Biomedical subjects

I Miller

Publications and source records attributed to I Miller.

At least 73 records · Page 4Linked to original sources
PubMed1993

Peculiarities in electrophoretic behavior of different serum albumins.

Behavior of serum albumins of different species was compared with regard to electrophoretic mobility under native conditions, molecular mass and isoelectric point in presence or absence of denaturing agents. In addition to serum samples from human, horse, cow, pig, cat, dog, sheep, goat, chicken, rabbit, mouse, and rat, commercially available standards or albumin preparations obtained by chromatographic procedures were analyzed. Feline and canine albumins showed marked differences in all investigated methods. Our experiments also revealed several factors influencing albumin patterns, especially during isoelectric focusing in immobilized pH gradients or in the presence of carrier ampholytes.

Animals↗
PubMed1992

Executive leadership, community action, and the habits of health care politics.

Health care executives must lead the way to the comeback of "voluntarism" in their field. This will require having four key political habits: (1) acting out of a sense of civic responsibility, (2) avoiding the dangers of faction and "magic bullets", (3) building alliances by a process of conferring with other relevant leaders and groups, and (4) participating in community activism, i.e., acting on, not reacting to, local problems and pressures.

Community Participation↗
PubMed1992

Immunomodulating activity of 1,2-difattyacyl-3-mercaptoglycerol adducts.

Adducts of 1,2-diacyl-(2RS)-3-mercaptoglycerol to 3-maleimidopropionic acid and to 3-maleimidopropionyl-L-alanyl-D-isoglutamine as well as a new lipophilic MTP derivative have been analysed for their immunomodulating activity in comparison to the well known adjuvants CFA and IFA using a suboptimal concentration of BSA as antigen. A concentration-dependent immunostimulating activity was established for these lipophilic molecules when applied in water/oil (IFA) emulsions. The results clearly indicate that the new series of compounds behave as competent adjuvants, a fact which is further supported by the immunoadjuvant effect triggered by two of these diacylthioglyceryl adducts as examples, even when applied in aqueous systems. In the light of these findings it seems promising to use these thiol-functionalized molecules to build in immunoadjuvancy via the maleimide-thiol reaction principle. Attachment of such "sticky fingers" to peptides might enhance interaction of haptens and immunogens with cell membranes and thus, may represent a useful tool for inducing or increasing immunological responses to synthetic antigen presenting systems.

Adjuvants, Immunologic↗
PubMed1992

[Electrophoretic studies of serum protein fractions in horses with laminitis].

The spectrum of serum proteins was evaluated in 46 horses affected with spontaneous laminitis and correlations between the severity of the disease and changes of the protein pattern were analyzed. The investigation was made in two groups; group A consisted of 21 horses of various breeds (warmblood, thoroughbred, standardbred) and group B of 25 ponys. Each group was subdivided according to the severity of the disease, using the OBEL-grade (OG) classification system. Serum proteins were separated by different one- and two-dimensional electrophoretic methods. Sera analysed by cellulose acetate electrophoresis showed a significant difference in the alpha 1-globulin fraction between OG II and OG IV affected horses. An increasing severity of the disease was correlated with a decrease of the alpha 1-globulins. The other protein fractions didn't show a uniform tendency. In group B there was a significant difference in the alpha 1-globulin fractions of OG II and OG III and in the beta 2-globulin fractions of OG I and OG II affected ponys. The acute phase proteins C3c, C4, Hp and fibronectin could be determined in a preliminary study in horse serum using the cross-reactivity of antibodies against the homologous human proteins.

Animals↗
PubMed1992

[Toxic effects in rabbits after immunization against the pyrrolizidine alkaloid retrorsine].

Six rabbits were immunized against the pyrrolizidine alkaloid retrorsin, conjugated to bovine serum albumin. Seven i.v. inoculations were distributed over a period of half a year. The total antigen dose differed between animals. Towards the end of the experiment all animals (except 2 receiving the lowest antigen dose) suffered from apathy, anorexia and loss of body weight. Pathologically these symptoms correlated well with liver cirrhosis, gradually dependent on the total antigen dose. Blood-chemical parameters were disparate and contradictory.

Animals↗
PubMed1991

Two-dimensional electrophoresis in small gels for applications in veterinary medicine.

A versatile method for two-dimensional electrophoresis that can be performed easily, even in small routine laboratories, is described. The procedure combines a first-dimensional isoelectric focusing run in a PhastSystem with denaturing electrophoresis in a small vertical electrophoresis chamber. The described arrangement of two first-dimensional gel strips in the second dimension allows direct comparison of two related samples, eliminating most of the artifacts that usually lead to misinterpretations. The presented procedure can be conveniently adapted to the needs of each laboratory; at present, it is being extensively used to establish protein patterns of healthy individuals of different species, a prerequisite with regard to help and support diagnosis.

Animals↗
PubMed1991

The role of a stress-response protein in Salmonella typhimurium virulence.

We recently described the use of selective transposon mutagenesis to generate a series of avirulent mutants of a pathogenic strain of Salmonella typhimurium. Cloning and sequencing of the insertion sites from two of these mutants reveals that both have identical locations within an open reading frame that is highly homologous to a gene, htrA, encoding a heat-shock protein in Escherichia coli. DNA sequence analysis of S. typhimurium htrA reveals the presence of a gene capable of encoding a protein with a calculated Mr of 49316 that has 88.7% protein:protein homology with its E. coli counterpart. In E. coli, lesions in this gene, also known as degP, reduce proteolytic degradation of aberrant periplasmic proteins. Characteristics of the S. typhimurium htrA mutants, 046 and 014, in vivo and in vitro suggested that they are avirulent because of impaired ability to survive and/or replicate in host tissues. In vitro, the S. typhimurium htrA mutants 046 and 014 are not temperature-sensitive but were found to be more susceptible to oxidative stress than the parent, suggesting that they may be less able to withstand oxidative killing within macrophages.

Alkaline Phosphatase↗
PubMed1990

Defective secretion of mucilage is the cellular basis for agravitropism in primary roots of Zea mays cv. Ageotropic.

Root caps of primary, secondary, and seminal roots of Z. mays cv. Kys secrete large amounts of mucilage and are in close contact with the root all along the root apex. These roots are strongly graviresponsive. Secondary and seminal roots of Z. mays cv. Ageotropic are also strongly graviresponsive. Similarly, their caps secrete mucilage and closely appress the root all along the root apex. However, primary roots of Z. mays cv. Ageotropic are non-responsive to gravity. Their caps secrete negligible amounts of mucilage and contact the root only at the extreme apex of the root along the calyptrogen. These roots become graviresponsive when their tips are coated with mucilage or mucilage-like materials. Peripheral cells of root caps of roots of Z. mays cv. Kys contain many dictyosomes associated with vesicles that migrate to and fuse with the plasmalemma. Root-cap cells of secondary and seminal (i.e. graviresponsive) roots of Z. mays cv. Ageotropic are similar to those of primary roots of Z. mays cv. Kys. However, root-cap cells of primary (i.e. non-graviresponsive) roots of Z. mays cv. Ageotropic have distended dictyosomal cisternae filled with an electron-dense, granular material. Large vesicles full of this material populate the cells and apparently do not fuse with the plasmalemma. Taken together, these results suggest that non-graviresponsiveness of primary roots of Z. mays cv. Ageotropic results from the lack of apoplastic continuity between the root and the periphery of the root cap. This is a result of negligible secretion of mucilage by cells along the edge of the root cap which, in turn, appears to be due to the malfunctioning of dictyosomes in these cells.

Cell Membrane↗
PubMed1989

Isolation of orally attenuated Salmonella typhimurium following TnphoA mutagenesis.

One hundred fifty Tn5 IS50L::phoA (TnphoA) mutants of a mouse-virulent, nalidixic acid-resistant (Nalr), prototrophic Salmonella typhimurium strain, C5 Nalr, were isolated. None of the mutants were auxotrophs. Groups of 8 to 10 BALB/c mice were infected orally with each of 95 mutants with a dose equivalent to 20-fold the 50% lethal dose of the wild-type C5 Nalr strain, and deaths were counted over the next 28 days. Fifteen of the mutants failed to kill any mice, whereas all mice died following challenge with the other mutants. Nine of the 15 attenuated mutants exhibited a defect in lipopolysaccharide biosynthesis. The remaining six mutants were smooth. The TnphoA transposon of each of the smooth attenuated mutants was moved, using P22-mediated transduction, into a fresh C5 background, and all retransductants were still attenuated. Analysis of the membrane proteins of the attenuated mutants failed to reveal any alterations in detectable major outer membrane proteins, although colonies of two of the mutants exhibited a mucoid phenotype following growth on L-agar plates. Individual attenuated mutants differed in their abilities to translocate to livers and spleens of mice following oral infection. All of the smooth TnphoA mutants exhibited increased 50% lethal doses with respect to the wild type following intravenous infection of BALB/c mice. Southern analysis of DNA prepared from each of the mutants suggested that TnphoA had inserted into a number of different sites in the S. typhimurium genome. None of the TnphoA mutants had inserts in the virulence-associated plasmid.

Administration, Oral↗
PubMed1988

Lessons from Benjamin Franklin's civic leadership: the Pennsylvania Hospital story.

John Gardner has recently suggested that in a pluralistic society like ours there are many competing groups, each with its own purpose. This leads to fragmentation and conflict as various social systems and institutions interact and collide. We have seen this in health care where competition has eroded traditional provider-insurer-purchaser alliances and, for example, the access problem has grown rapidly. Leaders in such an environment, Gardner (1988) argues, must become involve with building more "mutually workable arrangements with systems external to their own... Leaders unwilling to do so are not serving the long-germ interest of their own constituents... Under the circumstances, all our leader must spend part of their time building community, dealing with polarization, and creating loyalty to the larger venture." Methods for building community in turbulent times are offered by our first health care social entrepreneur, Benjamin Franklin. The following case study presents Franklin's leadership style and the three-phase process of seeking the civic unity that created Franklin's leadership style and the three-phase process of seeking the civic unity that created Pennsylvania Hospital, the nation;s first community hospital. The discussion concludes with a consideration of Franklin's civic leadership in light of five leadership roles suggested by Gardner.

Community Health Services↗
PubMed1987

Circuit for the electromanipulation of plant protoplasts.

An electric circuit for plant protoplast manipulation is described. The circuit used readily available materials and was designed for use in teaching. This integrated circuit can be placed in a single small box with controls for the aligning voltage, the aligning frequency, the pulse voltage, and the pulse timing. The circuit can be supplied by any suitable source of dc power and can be easily altered for individual requirements. The circuit, as presented here, can be assembled for less than $250.

Cell Fusion↗
PubMed1987

Interpreneurship: a community coalition approach to health care reform.

Interpreneurship-networking by coalitions to build innovative institutions to address community and societal problems-has been a vital force in America since colonial times. In this paper, I describe the interpreneurial framework of today: the five steps that seem necessary to effect fundamental change in a community and the four factors that must be considered in attempts to effect change. As an example of this framework, I describe the activity that led to the creation of a health maintenance organization in the early 1970s in Cincinnati. This case study-in which a Blue Cross Plan played a pivotal role-and my discussion of specific avenues for action might be helpful to communities that wish to develop an interpreneurial reform strategy for change.

Blue Cross Blue Shield Insurance Plans↗
PubMed1984

The effect of polyvalent metal ion mordanting on caries-like lesion progression in enamel.

The ability of metal ion mordanting followed by APF application to inhibit the progression of caries-like lesions was compared with APF treatment alone. The progression of the lesion was investigated in vitro using an acidified gel system, and the lesions were compared using polarized light microscopy. Both ferric and zirconyl pre-treatments, but not titanium, were shown to inhibit lesion progression to a greater extent than did APF. This inhibition was thought to be due to the presence of an amorphous-type coating similar to those produced on sound enamel by metal ion mordanting.

Acidulated Phosphate Fluoride↗
PubMed1984

Microprobe and SEM analysis of surface coatings on caries-like lesions in enamel after metal ion mordanting and APF application.

The production of tenacious surface coatings on enamel after metal ion mordanting followed by APF has been reported to prevent caries-like lesion initiation in vitro. In this study, similar surface coatings, which may be responsible for the inhibition of lesion progression, were examined using SEM and microprobe analysis. Relatively thick, even surface coatings which were in intimate contact with the enamel surface of caries-like lesions were seen after zirconium and iron (ferric) pre-treatment, but a thinner and unevenly distributed coating was seen after titanium pre-treatment. This latter coating was similar to that seen after APF treatment alone. Fluoride concentrations on the surface and in the subsurface of caries-like lesions were similar for all treatment groups. The surface coatings after zirconium and iron mordanting may be responsible for the greater inhibition of lesion progression than that seen after both titanium pre-treatment and APF treatment alone.

Acidulated Phosphate Fluoride↗
PubMed1984

A model for producing caries-like lesions in enamel and dentin using oral bacteria in vitro.

Subsurface enamel lesions and root surface caries-like lesions were consistently produced in vitro using Streptococcus mutans FA1 cultured in thioglycollate broth containing 3.5% w/v dextrose and 2% w/v gelatin. When viewed in polarized light and after imbibition in water, the enamel lesions had a negatively birefringent surface zone and positively birefringent body of the lesion. Those lesions produced after six weeks, after imbibition in quinoline, exhibited a dark zone. The root surface caries-like lesions exhibited a less-radiolucent surface zone above a heavily demineralized body of the lesion. However, no reactionary dentin was seen in the in vitro lesions.

Dental Caries↗