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Biomedical subjects

J L Miller

Publications and source records attributed to J L Miller.

At least 145 records · Page 8Linked to original sources
PubMed1999

Thirty years of cardiac transplantation at Stanford university.

BACKGROUND: The experience with 30 years of cardiac transplantation at Stanford University Medical Center was reviewed. A total of 954 transplants were performed in 885 patients. Patients were divided into 3 groups based on immunosuppression received: group I, no cyclosporine (INN: ciclosporin) (n = 201) (January 1968-November 1980); group II, cyclosporine (n = 248) (December 1980-June 1987); and group III, cyclosporine + OKT3 (n = 436) (July 1987-March 1998). RESULTS: The 1-, 5-, and 10-year actuarial survivals were 68%, 41%, and 24% (group I); 80%, 57%, and 37% (group II); and 85%, 68%, and 46% (group III) (I vs II, P <.01; I vs III, P <.005; and II vs III, P <.005). The 1-, 5-, and 10-year actuarial death rates from rejection were 8%, 12%, and 14% (group I); 5%, 7%, and 7% (group II); and 2%, 5%, and 5% (group III) (I vs II, P = not significant; I vs III, P <.005; and II vs III, P <.005). The 1-, 5-, and 10-year actuarial death rates from infection were 25%, 43%, and 50% (group I); 8%, 17%, and 29% (group II); and 6%, 11%, and 16% (group III) (I vs II, P <.005; I vs III, P <.005; and II vs III, P <.05). The 1-, 5-, and 10-year actuarial death rates from graft coronary artery disease were 0%, 5%, and 13% (group I); 0%, 12%, and 19% (group II); and 1%, 6%, and 9% (group III) (I vs II, P <.01; I vs III, P <.005; and II vs III, P = not significant). There have been 69 retransplants in 67 patients with 1-, 5-, and 10-year actuarial survivals of 49%, 27%, and 15%, respectively. CONCLUSIONS: The evolution of 3 decades of experience with cardiac transplantation has resulted in improved overall survival. The incidence of rejection and of death from infection and graft coronary artery disease have decreased over time, primarily as a result of improvements in immunosuppression and in the prevention and treatment of infection. Continued advances in perioperative management and the development of more specific, less toxic immunosuppressive agents could further refine this initial experience and improve the survival and quality of life of patients after cardiac transplantation.

Academic Medical Centers↗
PubMed1999

Prospective identification of erythroid elements in cultured peripheral blood.

We have developed a prospective approach to identify the generation of erythroid cells derived from cultured peripheral blood mononuclear cells (PBMC) by monitoring the expression of the cell surface protein CD48. Unpurified populations of PBMC obtained from the buffy coats of normal volunteers were grown in suspension culture in the absence or presence of erythropoietin. A profile of surface CD48 expression permitted a flow cytometric identification of erythropoietin responsive populations at various stages of their maturation. In the absence of erythropoietin (EPO) supplemented media, the CD48- cells represented <5% of the total population of PBMC remaining in culture. In cultures supplemented with 1 U/mL EPO, the mean percentage of CD48- cells increased to 34.7 + 14.9% (p < 0.01) after 14 days in culture. Coordinated CD34 and CD71 (transferrin receptor) expression, morphology, gamma-globin transcription, and colony formation in methylcellulose were observed during the 14-day culture period. Flow cytometric monitoring of bulk cultured PBMC provides a simple and reliable means for the prospective or real-time study of human erythropoiesis.

Adult↗
PubMed1999

The North American experience with photopheresis.

Photopheresis or extracorporeal photochemotherapy (ECP) is a novel immunomodulatory therapy based upon pheresis of light-sensitive cells. Whole blood is removed from patients who have previously ingested the photosensitizing agent 8-methoxypsoralen (8-MOP) followed by leukapheresis and exposure of the 8-MOP containing white blood cells (WBCs) extracorporeally to an ultraviolet A (UVA) light source prior to their return to the patient. In 1988, the Food and Drug Administration (FDA) approved photopheresis for the treatment of cutaneous T-cell lymphoma (CTCL). Treatment of CTCL with photopheresis has been reported in over 300 patients worldwide. Photopheresis has also demonstrated encouraging results in the treatment of solid organ transplant rejection, graft versus host disease, scleroderma, and other autoimmune diseases although fewer patients have been studied. This review will focus on the North American experience with photopheresis.

Arthritis, Rheumatoid↗
PubMed1999

Biotinylation modifies red cell antigens.

BACKGROUND: Chemical biotinylation of red cell membranes may be useful for several clinical applications, including red cell survival studies. STUDY DESIGN AND METHODS: To examine the possible effects of biotinylation on red cell antigens, standard hemagglutination assays were performed on matched sets of control and biotinylated red cells. The red cells were biotinylated at a final concentration of 2.0 pg of sulfo-N-hydroxysuccinimide-biotin per cell, and antigen-negative cells were directly compared to antigen-positive cells when possible. The hemagglutination assays were graded in a blinded fashion. Forty-one red cell antigens from 21 of the 23 established blood group systems were tested. RESULTS: Hemagglutination based upon antibody binding to A, A1, M, N, S, s, P1, D, C, E, c, e, C(w), Lu(b), K, k, Kp(b), Le(a), Le(b), Fy(a), Fy(b), Jk(a), Jk(b), Di(a), Wr(a), Wr(b), Yt(a), Xg(a), Sc1, Do(b), Co(a), Ch, H, Ge2, Cr(a), Kn(a), I, and P was not affected by biotinylation. Unexpectedly, the hemagglutination of Di(b+) and LW(a+) red cells was blocked after biotinylation. Conversely, MH04 monoclonal anti-A agglutinated red cells expressing B only after biotinylation. BIRMA-1 monoclonal anti-A and polyclonal anti-A from sera did not agglutinate the biotinylated B red cells. CONCLUSION: Biotinylation of human red cells specifically modified their antigenicity, as measured by standard hemagglutination assays.

Biotinylation↗
PubMed1999

Effects of syllable-initial voicing and speaking rate on the temporal characteristics of monosyllabic words.

Two speech production experiments tested the validity of the traditional method of creating voice-onset-time (VOT) continua for perceptual studies in which the systematic increase in VOT across the continuum is accompanied by a concomitant decrease in the duration of the following vowel. In experiment 1, segmental durations were measured for matched monosyllabic words beginning with either a voiced stop (e.g., big, duck, gap) or a voiceless stop (e.g., pig, tuck, cap). Results from four talkers showed that the change from voiced to voiceless stop produced not only an increase in VOT, but also a decrease in vowel duration. However, the decrease in vowel duration was consistently less than the increase in VOT. In experiment 2, results from four new talkers replicated these findings at two rates of speech, as well as highlighted the contrasting temporal effects on vowel duration of an increase in VOT due to a change in syllable-initial voicing versus a change in speaking rate. It was concluded that the traditional method of creating VOT continua for perceptual experiments, although not perfect, approximates natural speech by capturing the basic trade-off between VOT and vowel duration in syllable-initial voiced versus voiceless stop consonants.

Female↗
PubMed1999

Hypertrophy of skeletal muscle in diabetic rats in response to chronic resistance exercise.

This study had the following objectives: 1) to determine whether diabetic rats could increase muscle mass due to a physiological manipulation (chronic resistance exercise), 2) to determine whether exercise training status modifies the effect of the last bout of exercise on elevations in rates of protein synthesis, and 3) to determine whether chronic resistance exercise alters basal glycemia. Groups consisted of diabetic or nondiabetic rats that performed progressive resistance exercise for 8 wk, performed acute resistance exercise, or remained sedentary. Arterial plasma insulin in diabetic groups was reduced by about one-half (P < 0.05) compared with nondiabetic groups. Soleus and gastrocnemius-plantaris complex muscle wet weights were lower because of diabetes, but in response to chronic exercise these muscles hypertrophied in diabetic (0.028 +/- 0.003 vs. 0.032 +/- 0.0015 g/cm for sedentary vs. exercised soleus and 0.42 +/- 0.068 vs. 0.53 +/- 0.041 g/cm for sedentary vs. exercised gastrocnemius-plantaris, both P < 0.05) but not in nondiabetic (0.041 +/- 0.0026 vs. 0.042 +/- 0.003 g/cm for sedentary vs. exercised soleus and 0.72 +/- 0.015 vs. 0.69 +/- 0.013 g/cm for sedentary vs. exercised gastrocnemius-plantaris) rats when muscle weight was expressed relative to tibial length or body weight (data not shown). Another group of diabetic rats that lifted heavier weights showed muscle hypertrophy. Rates of protein synthesis were higher in red gastrocnemius in chronically exercised than in sedentary rats: 155 +/- 11 and 170 +/- 7 nmol phenylalanine incorporated x g muscle(-1) x h(-1) in exercised diabetic and nondiabetic rats vs. 110 +/- 14 and 143 +/- 7 nmol phenylalanine incorporated x g muscle(-1) x h(-1) in sedentary diabetic and nondiabetic rats. These elevations, however, were lower than in acutely exercised (but untrained) rats: 176 +/- 15 and 193 +/- 8 nmol phenylalanine incorporated x g muscle(-1) x h(-1) in diabetic and nondiabetic rats. Finally, chronic exercise training in diabetic rats was associated with reductions in basal glycemia, and such reductions did not occur in sedentary diabetic groups. These data demonstrate that, despite lower circulating insulin concentrations, diabetic rats can increase muscle mass in response to a physiological stimulus.

Animals↗
PubMed1999

Stable expression of green fluorescent protein after liposomal transfection of K562 cells without selective growth conditions.

Little is known about the durability of plasmid DNA transgene expression in mammalian cells in the absence of growth selection. For this purpose, we have begun the study of liposomal transfer and expression of plasmid DNA encoding green fluorescent protein (GFP) in human erythroleukemia K562 cells. Detection and selection of GFP expression were accomplished visually and by flow cytometry. GFP expression was noticeable in cells within 4 h of transfection. In nine separate transfections, approximately 20% of the transfected cells expressed GFP with a mean fluorescence 40-50x that of control cells (15 fluorescent units [FU] vs. 0.3 FU) during the first five days after transfection. The percentage of GFP positive cells dropped rapidly to 0.1% by day 14 post-transfection, but fluorescence activated cell sorting on this day resulted in the identification of stable transfectants expressing GFP for an additional 6-12 months in culture. GFP expression is adequate for the identification, isolation and monitoring of stable transfection events after lipid-mediated transfection of eukaryotic cells.

Blotting, Southern↗
PubMed1998

Variegated transfer of recombinant glycosylphosphatidylinositol-anchored CD4 among cultured cells: correlation of flow cytometric and microscopic observations.

Glycosylphosphatidylinositol-anchored proteins (GPI-proteins) expressed on the outer leaflet of cell membranes are involved in diverse physiologic as well as pathologic processes in humans. Previously, we demonstrated the intercellular transfer of overexpressed CD4-GPI in vitro from transduced HeLa cells to their parental cell line. In this report we present further information on the transfer process and the nature of the transferred GPI-proteins. In mixed-cell populations, the transfer of CD4-GPI was detectable within minutes at levels proportional to the ratio of donor and recipient cells. The amount of CD4-GPI detected with flow cytometry on the surface of the recipient cells varied according to cell type. Microscopy of mixed cell populations revealed discrete CD4-GPI containing aggregates on the target cells, whereas colocalized transfer of cytoplasm was not detected. Separation of cocultivated cells by semipermeable membranes largely prevented CD4-GPI transfer, but aggregates containing CD4-GPI were demonstrated by electron microscopy in supernatants passed through filters of 0.4-mm pore size.

Animals↗
PubMed1998

Demographic and health status indicators to guide health promotion for Hispanic and Anglo rural elderly.

Naturally occurring differences rather than simple breakdowns by ethnic category are being used to tailor strategies in a three year senior community health worker-delivered health promotion intervention. A survey conducted of persons 60 and over in a rural southwestern U.S. community identified New Anglos (recent settlers, n = 264), Old Anglos (long-time residents, n = 298) and Hispanics (n = 236) for a total of 798 persons. Significant demographic differences included less education, poorer health status and more chronic conditions among Hispanics. Low rates of screening were the norm but especially severe among Old Anglos. Patterned differences in health practices, as well as group variations in use of resources and sources of information, revealed New Anglos used a larger variety of services and media. Generally, adjustments being made are related to Hispanic culture, cosmopolitan orientation of the New Anglos, and long-term isolation from information and services for Old Anglos.

Aged↗
PubMed1997

Long-term, stable expression of green fluorescent protein in mammalian cells.

Despite the proven utility of green fluorescent protein (GFP) as a reporter molecule for transient gene expression, the adequacy of this marker for models requiring durable, high-level gene expression has not been fully tested. To address this issue, we performed the transfection of Chinese Hamster Ovary (CHO) cells with plasmid DNA encoding both GFP and neomycin phosphotransferase (neo) cassettes. The expression of GFP was measured after the cells were cultured in the presence or absence of G418-mediated selective pressure. After removal of G418 from the growth medium, the percentage of pooled G418 resistant transfectants which co-expressed the GFP transgene increased or remained unchanged. Flow cytometric and visual isolation of GFP-expressing cells was possible without continued selection in G418. One cloned cell line, C463, maintained high-level green fluorescence for 18 weeks in G418 and an additional 12 weeks in nonselective medium. Our data suggest expression of GFP does not confer a growth disadvantage in mammalian cells.

Animals↗