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Biomedical subjects

C Lee

Publications and source records attributed to C Lee.

At least 865 records · Page 48Linked to original sources
PubMed1987

The neurotoxicity of high-dose cytosine arabinoside is age-related.

Fifteen patients with acute myeloid leukaemia were given a total of 17 courses of high-dose cytosine arabinoside (Ara-C). The median age of the patients was 37 years. Four patients developed severe irreversible neurotoxicity, three developed mild to moderate, reversible neurotoxicity, whereas eight patients had no toxicity. Of five patients over the age of 55 years given high dose Ara-C, four developed severe, irreversible neurotoxicity, but there were no severe episodes in nine patients aged 55 years or less. (P less than 0.01). At a dose of 3 g/m2 given intravenously every 12 hours for 3 days, three cases of severe irreversible neurotoxicity were noted in elderly patients. Neurotoxicity at this total dose has previously been considered unusual. Administration of high dose Ara-C at total doses of 18 g/m2 and over carries a risk of severe irreversible cerebellar toxicity that increases with age.

Activities of Daily Living↗
PubMed1987

Norfloxacin: its potential in clinical practice.

The in vitro spectrum and potency of norfloxacin against both aerobic gram-negative and gram-positive bacteria, its limited activity against anaerobes, and the apparent difficulty organisms have in acquiring resistance to it, have provided a rationale for the clinical development of this oral fluoroquinolone antimicrobial agent. The clinical experience with norfloxacin as treatment for a variety of urinary tract infection syndromes, uncomplicated gonococcal infection, and diarrheal disease, and as prophylaxis of infection in neutropenic patients with cancer, is reviewed. Norfloxacin appears at least equivalent to standard regimens for the treatment of acute urinary tract infections; however, long-term studies are needed to define its role in the treatment of recurrent urinary infections. Initial studies of norfloxacin treatment of uncomplicated gonococcal infection and bacterial gastroenteritis are also promising, and in neutropenic patients, continuous norfloxacin prophylaxis has been shown to reduce the incidence of gram-negative infections. Further prospective evaluation is required to confirm these findings.

Bacterial Infections↗
PubMed1987

Kupffer cell modulation of the systemic immune response.

The effects of global hepatic injury and of Kupffer cell activation on systemic immunity were studied in an in vivo rat model, using the diameters of the delayed-type hypersensitivity (DTH) response to keyhole limpet hemocyanin and of a subcutaneous Staphylococcus aureus abscess as measures of systemic immunoresponsiveness. Hepatic injury with carbon tetrachloride resulted in significant suppression of the DTH score (5.5 +/- 0.7 vs 8.8 +/- 0.8 mm). Kupffer cell activation with intraportal Escherichia coli was likewise suppressive (DTH score, 4.4 +/- 0.5 vs 6.1 +/- 0.4 mm for animals receiving systemic E coli); the magnitude of this suppression correlated with the numbers of organisms extracted by the liver. Conversely, Kupffer cell ablation with carrageenan lessened the immunosuppressive effects of anesthesia and surgery (DTH score, 8.5 +/- 0.9 vs 6.8 +/- 0.6 mm for controls; S aureus abscess, 4.1 +/- 0.4 vs 5.7 +/- 0.4 mm for controls). These results indicate that Kupffer cells can modulate the systemic immune response and suggest that gram-negative portal bacteremia with resultant Kupffer cell activation may contribute to the immunologic derangements characteristic of trauma and critical surgical illness.

Animals↗
PubMed1987

Expression of HLA-DR and OKT6 antigens on keratinocytes and dendritic cells in pemphigus.

The expression of HLA-DR and OKT6 antigens by epidermal cells in pemphigus was examined by immunohistochemical methods using skin biopsy specimens from human patients with pemphigus vulgaris. Changes in the distribution and subpopulations of Langerhans cells were observed in lesional (involved) skin. HLA-DR-positive, OKT6-negative dendritic cells were numerous and generally confined to the margins of epidermal clefts. OKT6-positive dendritic cells were rare or absent in lesional skin. The HLA-DR-positive, OKT6-negative dendritic cells associated with intraepidermal clefts are most likely functionally active antigen-presenting cells, which may play a role in lesion development. Aberrant expression of HLA-DR molecules by keratinocytes was observed in both involved and uninvolved skin, and may function to facilitate the recognition of surface-bound pemphigus antigen(s) by immunocompetent cells.

Antibodies, Monoclonal↗
PubMed1987

Affective behavior modification: a case for empirical investigation.

Recent developments in behavioral and cognitive-behavioral theory emphasize the relationships between behavior, cognition, and effect, and their importance in understanding and modifying human behavior. This paper reviews some current arguments concerning these relationships, and outlines some possible implications for the future development of behavioral theory and practice. Some recent trends towards models which invoke complex and unobservable mechanisms to explain affect may provide a temporarily convenient framework for talking about highly complex phenomena. But it should be remembered that these models are not empirically verifiable. A focus on variables which can be defined and measured objectively is essential for the scientific development of behavioral theories that have real explanatory value, and for behavior modification practice.

Association↗
PubMed1987

Proteins of the rat prostate. II. Synthesis of new proteins in the ventral lobe during castration-induced regression.

Ventral prostates from adult Sprague-Dawley rats at different days postcastration were cut into one to two mm.3 pieces and incubated in medium containing S35-methionine (100 uCi/ml.) at 37C under 95% oxygen and 5% carbon dioxide for four hours. The incubated tissues were subjected to two-dimensional electrophoresis and radiofluorography. Over 100 spots were developed in the fluorograms. Three groups of spots, representing cytoskeletal proteins, androgen-dependent proteins and castration-induced proteins, were further evaluated by a computer-based densitometer. The level of densitometry absorption is proportional to the amount of radioactivity in each spot. The synthesis of cytoskeletal proteins, such as actin and tropomyosin, were relatively constant throughout the course of prostatic regression. The rate of synthesis of androgen-dependent proteins declined rapidly from a high level of synthesis before castration to a non-detectable level by Day 3 postcastration. However, three proteins, which were either not synthesized (spot G and spot H) or synthesized at a very low level (spot I) before castration, were the major proteins synthesized by the prostate during early stages of its regression. The rate of synthesis of these proteins reached a peak by Day 4 postcastration, declined rapidly and remained at a low level thereafter. The respective molecular weights and isoelectric points for these three proteins were 33 Kd and 7.2 for spot G, 38 Kd and 5.3 for spot H and 64 Kd and 6.0 for spot I. Previous findings showed that prostatic regression in rats was associated with a surge of activities in proteolytic enzymes which peaked five to six days postcastration. The peak of synthesis of three proteins noted in the present study, therefore, preceded the peak of activities of proteolytic enzymes in the regressing prostate by one to two days. Testosterone replacement to animals at the time of castration prevented the synthesis of these proteins in the prostate. Since the synthesis of these three proteins in the ventral prostate is induced by androgen-depletion resulted from castration, they are considered as the castration-induced proteins.

Animals↗
PubMed1987

T lymphocyte depletion of human peripheral blood and bone marrow using monoclonal antibodies and magnetic microspheres.

It has previously been demonstrated that graft-versus-host disease can be overcome in patients receiving HLA-mismatched bone marrow transplants by prior in vitro depletion of T lymphocytes from the marrow. In this report we describe the use of monoclonal antibodies and magnetic microspheres for the depletion of T cells from peripheral blood and bone marrow. The target cells are sensitized with antibodies directed against the CD2, CD3, CD4 and/or CD8 cell surface antigens, captured by magnetic beads coated with sheep anti-mouse IgG antibody and collected by placing the cell suspension in a magnetic field. This simple, rapid procedure results in the efficient removal of T cells from peripheral blood and from bone marrow without affecting the colony-forming potential of normal hematopoietic stem cells. The procedure is capable of being scaled up for the treatment of larger volumes of marrow that are required for clinical transplantation.

Antibodies, Monoclonal↗
PubMed1987

Hemodynamic and neurohumoral factors in the response of hypertensives to hydrochlorothiazide therapy.

We investigated the roles of the renin-angiotensin-aldosterone axis, the sympathetic nervous system, and the responses of the forearm vascular bed in the antihypertensive action of hydrochlorothiazide. Plasma renin activity, aldosterone, catecholamines, blood pressure, and forearm blood flow were measured before and after 8 weeks of hydrochlorothiazide therapy in 21 hypertensive patients whose blood pressures responded to the diuretic, and were then compared to a similar group of 19 hypertensives who did not respond to the thiazide therapy. Dietary salt intake was stable and comparable for the two groups. In the responsive patients, administration of the diuretic caused a significant fall in supine systolic and diastolic blood pressure and forearm vascular resistance, with constant forearm blood flow. No significant changes were noted in these parameters in the non-responsive group. Plasma renin activity and aldosterone concentration was increased in both groups to a comparable extent but plasma norepinephrine and epinephrine concentrations were increased to a greater extent (p less than 0.01) in the responsive group. Heart rate did not change significantly in either group in spite of significant increases in circulating epinephrine. The results are consistent with minimal thiazide-induced volume and salt depletion in either study group. The reduction in blood pressure and forearm vascular resistance observed in the responsive group appears to be the result of diminished target-organ sensitivity towards catecholamines and possibly angiotensin II.

Aldosterone↗