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Biomedical subjects

B Anderson

Publications and source records attributed to B Anderson.

At least 487 records · Page 27Linked to original sources
PubMedDate not supplied

Inhibition of mouse mammary adenocarcinoma (EMT6) growth and metastases in mice by a modified form of C-reactive protein.

Mice were injected in the hind limb with a mouse mammary adenocarcinoma cell line, EMT6, and tumor growth at the primary site as well as the incidence of lung metastases were measured. Groups of animals were treated with the acute-phase reactant C-reactive protein, (native-CRP), or a conformationally modified form of CRP (mCRP) made by dissociating CRP subunits under chelating, denaturing conditions. Each form of CRP was injected (intravenously) through the tail vein, encapsulated in large unilamellar lipid vesicles made by an extrusion technique (LUVETs). mCRP was also injected without the LUVET carrier. Mice not treated, or treated with LUVETs alone, exhibited both progressive tumor growth at the primary site and a high incidence of metastatic lung tumors quantified at necropsy. Treatment with native-CRP encapsulated in LUVETs had little or no effect on either tumor growth or metastases. Treatment with mCRP, however, alone or encapsulated in LUVETs, effectively slowed or stopped the progression of tumor growth, and in some mice, showed a decrease in tumor size. After cessation of mCRP injections, tumor growth resumed at a rate comparable to that measured in untreated animals. Fifty to 85% of mice treated with mCRP or mCRP in LUVETs developed necrotic lesions at the primary tumor site within 24-48 h following the initial injection of protein. Furthermore, at necropsy, only 6% of mice treated with mCRP in LUVETs and 40% of mice treated with mCRP alone showed evidence of lung metastases compared to 67-80% of animals in no-treatment, native-CRP in LUVETs and in LUVET control group animals. These results show that the prototypic acute-phase reactant, CRP, has therapeutic anticancer and antimetastatic activity only when the native pentameric subunit structure is dissociated to form the mCRP conformer.

Adenocarcinoma↗
PubMedDate not supplied

Microvascular endothelium of human tumor xenografts expresses mouse (= host) CD31.

BACKGROUND: Human malignant tumors grown as xenografts in immunocompromised animals have been used extensively to study tumor growth and tumor response to therapy. The endothelium functions as an effective barrier between the intravascular space and the tumor cells. In a previous study we used species-specific monoclonal antibodies against endothelial cell adhesion molecules to demonstrate the host origin of the endothelium in xenotransplanted pancreatic islet grafts [Am J Pathol 1995;146:1397-1405]. We now investigated in this study whether the vascular endothelium of different xenografted human malignant tumors expresses mouse (= host)- or human (= graft)-specific CD31 (platelet endothelial cell adhesion molecule, PECAM-1) adhesion molecules. METHODS AND RESULTS: Cultured human prostate, kidney, and colon cancer cells (passages 15-17) were transplanted subcutaneously into 8-week-old athymic nude mice and removed after another 8 weeks. The avidin biotin peroxidase method was utilized on frozen sections to demonstrate that the endothelium of the vasculature of all three human xenografts expressed mouse (= host)-specific CD31, but not human (= graft)-specific CD31. CONCLUSION: The presence between the intravascular space and the human tumor cells of a mouse-derived endothelium, expressing mouse-specific antigens, needs to be taken into careful consideration when evaluating results of antitumor therapies in these animal models. This caveat pertains particularly to the study of novel cell- or tissue-specific treatment modalities, such as antibody-targeted drugs, toxins or radionuclides, 'immuno'-liposomes, or tumor vaccines.

Animals↗
PubMedDate not supplied

Mental illness: diagnosis or value judgment?

This article is concerned with the definition of mental illness. Although it seems that it cannot be defined clearly in a legal or scientific way, this does not necessarily mean that health treatment is arbitrary and ill-founded.

Attitude to Health↗
PubMedDate not supplied

Laboratory evaluation of new reusable blood glucose sensor.

An enzyme-electrode sensor designed specifically for pocket-portable self-monitoring of blood glucose is described. The sensing device in this instrument is unique because it is reusable for at least 30 days, at which time it is easily replaced by placing a new enzyme-membrane cartridge over the electrode. As little as 7 microliters of undiluted whole blood, plasma, or serum is applied directly to the sensor, and glucose is automatically determined in 30 s. No manual timing or wiping step is required after sample application. On eight production instruments, plasma glucose concentration was determined (n = 20) at 57, 125, 246, and 347 mg/dl. The average coefficient of variation for the 80 determinations for each instrument ranged from 2 to 5%, averaging 3.7%. The instrument is inherently linear, independent of hematocrit, and without oxygen limitation when dissolved oxygen concentration is greater than 35 mmHg. No interferences were found from plasma constituents, heparin, or acetaminophen.

Biosensing Techniques↗
PubMedDate not supplied

Brain arteriovenous malformations: assessment with dynamic MR digital subtraction angiography.

BACKGROUND AND PURPOSE: Conventional catheter angiography (CCA) is the current reference standard for the diagnosis, assessment, and management of pial brain arteriovenous malformations (AVMs). The purpose of this study was to develop an MR angiographic technique that produces dynamic images comparable to those provided by CCA and to apply the technique to the investigation of pial brain AVMs. METHODS: Twenty patients with brain AVMs referred for stereotactic radiosurgery were recruited. All patients had CCA performed on a 1.5-T superconducting system. Sixty images were obtained at a rate of one image per second. Slices were orientated to produce Towne, lateral, and anteroposterior projections. A set of mask images was taken and then a series during the passage of a bolus of contrast material. MR examinations were assessed independently by neuroradiologists blinded to the conventional catheter angiographic findings. RESULTS: The nidus of the AVMs was depicted in 19 of the 20 patients, and correlation with CCA was excellent for measurements of maximum diameter. Venous drainage was correctly assessed in 18 of 19 cases. CONCLUSION: MR digital subtraction angiography shows promise as a noninvasive, dynamic angiographic tool for planning stereotactic radiosurgery of AVMs already delineated by catheter angiography. At present, it suffers from temporal and spatial resolution, which impede the assessment of some brain AVMs.

Adolescent↗
PubMedDate not supplied

Differences of antigen composition of rheumatoid arthritic (RA) and non-RA derived tissue cultured synovial cells as detected by monkey anti-RA synovial cell sera.

Antisera produced in a monkey by injections of RA-derived synovial cells grown in tissue culture react preferentially with synovial cells compared to fibroblastic cell strains of other tissues. The antisera also detected differences of the antigenic components of RA and non-RA synovial cells utilizing a number of immunochemical techniques. Following adsorptions with cross-reactive antigen sources the antisera exhibited quantitative differences of reactivity to either RA or non-RA cells by immunofluorescence and complement-mediated cytotoxicity assays. The data were interpreted as indicating that fetal calf serum antigens differentially adhere to RA and non-RA synovial cells, and that antigens in synovial fluid cross-reactive with synovial cell antigens are expressed to a greater degree on RA-derived synovial cells. The results substantiate other reports that synovial cells from RA individuals are different from non-RA cells by a number of growth, metabolic and antigenic characteristics.

Adsorption↗
PubMedDate not supplied

Fibronectin in rheumatoid and non-rheumatoid arthritic synovial fluids and in synovial fluid cryoproteins.

Concentrations of fibronectin, immunoglobulins G, M, and A, and C3 and C4 components of complement, and other plasma proteins were determined in synovial fluids from patients with rheumatoid arthritis (RA) and other diseases (non-RA). Fibronectin concentrations were two to three times greater in all synovial fluids than in plasma, and RA synovial fluids had a significantly higher mean concentration than non-RA fluids (883 microgram per ml vs. 588 microgram per ml, respectively, p less than 0.01). The mean concentrations of other synovial fluid constituents were less than their mean plasma concentrations. These results suggest that unlike other plasma constituents, either plasma fibronectin is concentrated in synovial fluids or that a substantial portion of synovial fluid fibronectin may be derived from synovial tissue cells. Both the C3 and C4 complement components were present in lower concentrations in RA than in non-RA synovial fluids. The C3 contents showed a statistically significant negative correlation with the fibronectin contents. Fibronectin was also found in all synovial fluid cryoprotein fractions tested, although its content varied greatly as a percent of the total cryoprotein protein (0.01 to 43 percent). The data show that fibronectin is a consistent constituent of synovial fluid cryoproteins in agreement with our previously reported finding that fibronectin is found in all serum cryoglobulin fraction tested.

Arthritis↗