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Biomedical subjects

M Zborowski

Publications and source records attributed to M Zborowski.

At least 37 records · Page 2Linked to original sources
PubMed1995

Analytical magnetapheresis of ferritin-labeled lymphocytes.

Analytical magnetapheresis is a technique for analyzing magnetic particles in suspension. The magnetically susceptible particles form a deposition pattern from the suspending medium under carefully controlled flow and magnetic field conditions. This technique was used to determine the effective magnetic volumetric susceptibility, delta chi, of human lymphocytes labeled with an iron-rich protein, ferritin. Dynabeads M450, monodisperse polymeric beads doped with magnetite, of a diameter 4.5 microns, close to that of human lymphocytes, were used as a reference. The experiment showed an almost complete deposition of ferritin-labeled lymphocytes at an average flow velocity of 0.28 mm/s, a representative magnetic field of 1.67 T, and a magnetic field gradient of 2.57 T/mm. The calculated delta chi was (2.92 +/- 0.24) x 10(-6)[SI] (ferritin-labeled lymphocytes), and the corresponding number of ferritin molecules per lymphocyte was (1.75 +/- 0.44) x 10(7). In comparison, an almost complete deposition of the Dynabeads was observed at a much higher average flow velocity, 15 mm/s, a much lower field, 0.164 T, and a much lower field gradient, 0.025 T/mm. These results corresponded to a much higher delta chi = 0.245[SI] (Dynabeads M450). These results offer important guidelines in evaluating the use of ferritin as a soluble magnetic cell label.

Calibration↗
PubMed1995

Extracorporeal techniques of endotoxin removal: a review of the art and science.

The incidence of sepsis in the United States has risen in the past few years, and mortality from sepsis has risen over the past several decades. These increases have occurred despite the progress made in antibiotic therapy. The high mortality rate may not be related to the bacteria themselves but rather to the host's response. Of particular concern is the bacterial release of endotoxins, the development of endotoxic shock, and the resulting multiorgan failure, which has a high fatality rate and is the leading cause of death in patients admitted to intensive care units. Removing or neutralizing endotoxins are the two major therapeutic approaches to treating sepsis. To date, pharmacological methods have not been successful. Extracorporeal techniques are based on filtration, sorption, or both. Results with hemofiltration have not been definitive, in part because endotoxin levels have not been measured. Sorption devices, based on polymyxin B and anion exchange matrices, do remove endotoxins. Clinical studies in Japan on septic shock or multiorgan failure with polymyxin-B-bound fibers in direct hemoperfusion continue to suggest the utility of extracorporeal techniques for endotoxin removal. Continued effort is required and warranted to assess the clinical efficacy of these techniques.

Endotoxins↗
PubMed1994

Defective leukocyte function-related cryoprecipitable protein in cryoglobulinemia.

Cryoprecipitable proteins (CPP), purified from plasmas removed during plasmapheresis treatment of patients with type II and type III cryoglobulinemia (CG), were evaluated in vitro for their effect on normal leukocyte function. CPP reduced normal mononuclear cell blastogenesis and polymorphonuclear cell phagocytosis responses in a dose-dependent fashion. At the maximum concentration studied, 5,000 micrograms/ml, CPP were shown to suppress normal blastogenesis and phagocytosis 30-60% and 50-80% below the albumin control, respectively. A 50% suppression of normal blastogenesis and phagocytosis was observed at 500 micrograms/ml for type III CPP. Leukocyte functions in CG patients were evaluated and compared to those of healthy controls. Blastogenesis and phagocytosis were significantly inhibited in CG patients. These studies suggest that CG patients have defective leukocyte function and that CPP have suppressive effects on normal leukocyte function. Our studies suggest that removal of CPP in CG patients may prove beneficial not only in reducing typical symptoms of CG but also in reducing the potential inhibitory effects of CPP on leukocyte function.

Adult↗
PubMed1993

A comparison of efficacy of Tołpa Torf Preparation (TTP) in the treatment of cervicitis with or without surgery.

Tołpa Torf Preparation (TTP) is an immunomodulating drug produced by Torf Corporation, Wrocław and registered for human use in Poland. TTP enhances the process of tissue regeneration. Authors evaluate TTP effectiveness in the treatment of inflammatory states of the cervix, especially cervical erosions and the influence of this preparation of the macroscopic, cytological and bacteriological state of the cervix. TTP was used in 31 patients with the diagnosis of cervical erosion. All patients treated as yet were classified into 3 groups, depending on the treatment of cervical erosion used previously. TTP was administered orally in the dose of 5 mg (in 10 ml of water) daily during 10 days and locally in the form of tampons soaked with 1% TTP solution in the volume of 5 ml also during 10 days. TTP administered this way has beneficial therapeutic effects on the healing of cervical erosion accelerating the process of epithelialization and bringing normalization of the cytological picture. Especially beneficial in the treatment of cervical erosion is combined use of TTP and electrocoagulation or curettage--the healing time can be shortened by half.

Adjuvants, Immunologic↗
PubMed1992

Selective removal of anti-acetylcholine receptor antibody in the low temperature operation of membrane plasma fractionation.

The removal of anti-acetylcholine receptor antibody (anti-AChR Ab) by the plasma fractionator, Kuraray EVAL 2A, was measured as a function of the filtration temperature (4 and 37 degrees C). Plasmas procured from eight myasthenia gravis (MG) patients undergoing routine plasma exchanges (PE: membrane plasma filtration: n = 4, and centrifugation: n = 4) were used in the studies. Plasma flow rate was 20 ml/min, and plasma perfusion in single pass was terminated when the transmembrane pressure of the filter reached 300 mm Hg. Solute concentration data from before and after perfusion were used to assess the sieving coefficient (SC) of each solute. Results show that the SCs for anti-AChR Ab and albumin were significantly (P < .0002) lower at 4 degrees C (0.15 and 0.52, respectively) as compared to 37 degrees C (0.44 and 0.72, respectively). The SC of anti-AChR Ab (0.15) was significantly lower than the SC of IgG (0.42; P < .006) at 4 degrees C, even though it also belongs to the IgG class. The ratio of the SC of anti-AChR Ab to albumin at 4 degrees C (0.29) was significantly lower than that at 37 degrees C (0.57; P < .003). These data indicate that the selectivity of removal of anti-AChR Ab from albumin is higher at 4 degrees C than that at 37 degrees C. The volume treated at 4 degrees C was significantly lower than that treated at 37 degrees C, and it was less than that required for a clinical treatment; however, it was shown that filter backwashing is possible without loss of solute removal selectivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗
PubMed1992

Backwashing procedure for on-line reuse of a plasma fractionator in cryofiltration.

During membrane plasma fractionation therapy there are reported incidences of membrane plugging requiring the corrective actions of either filter replacement or backwashing (BW) in order to continue the treatment. In this preliminary study, a simple BW procedure to allow for on-line reuse of the filter (Asahi AP06M) during the treatment was evaluated to assess its efficacy and safety in cryofiltration (CF). Evaluations were carried out on two patients treated for rheumatoid arthritis. Seven tests, each using 1 L or 2 L warmed saline as a BW solution were performed to evaluate the decrease of the transmembrane pressure (TMP) between just before and after backwashing and TMP change during cryofiltration procedures between before and after backwashing. Sieving coefficients of total protein, albumin, immunoglobulins (G, M, A), fibrinogen, and rheumatoid factor were also calculated at 1,000 ml plasma volume processed. Results showed statistically significant decreases of TMP from 300 mm Hg to 70 mm Hg between just before and after both backwashing procedures, and that there were no significant changes in the TMP increase during the cryofiltration procedure between pre- and post-BW. The protein sievings were not significantly affected by BW. The use of a second liter for rinsing did not reduce the inlet pressure further suggesting that 1 L BW was adequate. The accumulated solutes did not affect significantly the effective mean pore size. The BW procedure did not affect the overall patient safety during therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthritis, Rheumatoid↗
PubMed1992

Quantitative separation of bacteria in saline solution using lanthanide Er(III) and a magnetic field.

A trivalent lanthanide ion, erbium (Er3+), has been used in combination with a magnetic separation technique to isolate seven bacterial species from suspensions in 0.9% saline. Erbium has an exceptionally high atomic magnetic moment of 9.3 Bohr magnetons, and following addition as ErCl3 (final concentration 5 mM) to bacterial suspensions, it imparts the magnetic moment to the bacterial cells by ionic binding to the cell surface. Strains of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus epidermidis, Staphylococcus saprophyticus and Enterococcus faecalis were obtained from the Quality Control Depository of The Cleveland Clinic Foundation, Cleveland, Ohio, USA as suspensions in 0.9% NaCl, in concentrations ranging from 10(2) to 10(8) c.f.u. ml-1. Bacteria were separated from solution inside a capillary flow cell exposed to a highly non-homogeneous magnetic field (maximum field intensity was 0.4 T) and quantified by a light scattering method. The quantity of cellular deposition in the magnetic field was correlated with the initial concentration of cells in the suspension, expressed in c.f.u. ml-1, and sample volume (1.5 and 3.0 ml), sample pH (prior to ErCl3 addition), affinity to Gram stain (negative vs positive) and species.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteriological Techniques↗
PubMed1983

Respiratory gas exchange through the hydrophilic membrane.

To assess the efficiency of respiratory gas exchange in vitro through a dialysis membrane mounted inside a flat plate Kiil dialyzer, the model reactions of hydrogen peroxide reduction by a metal ion and of the carbon dioxide precipitation in the form of a carbonate in the dialysate were used. A comparison of the rates of oxygen output obtained for a membrane fixed in the test chamber and those for a membrane inside the dialyzer showed that the performance of the membrane as an oxygen source in the latter arrangement is much poorer than that in the former one. This was attributed to the inadequate dialysate channel geometry of the dialyzer with respect to the catalytic reaction. However, the dialyzer geometry did not impede a quick removal of carbon dioxide. Washout of the catalyst (cobalt oxide) was observed. Hydrogen peroxide leakage to the blood side of the membrane was negligible.

Biological Transport↗
PubMed1983

Theoretical prediction of the oxygen output for a dialysis membrane with a catalyst, in a flat plate dialyzer.

Mass transfer of a solute of small molecular weight across a hydrophilic membrane is discussed and a simplification of the mass transfer analysis is proposed. It was assumed that the permeability of the boundary layer at the membrane surface depends only on the velocity gradient at that membrane surface. Theoretical results are compared with the values of oxygen output at the dialysis membrane activated with an inorganic catalyst, in the presence of hydrogen peroxide, inside a test chamber of a simple geometry and in the flat plate dialyzer. Test chamber data and the theoretical analysis allow for the prediction of the mass transfer efficiency of the dialyzer.

Catalysis↗
PubMed1983

Carbon dioxide removal by a hemodialyzer with the dialysate channel coupled to the bubble oxygenator.

A combined dialyzer-oxygenator system that removes CO2 extracorporeally is described. This system was devised to support the exchange of gases through the natural lungs and to diminish the rate of extracorporeal blood flow during prolonged gas exchange. The total CO2 removed was 20 ml/m2-min at an inlet PCO2 of 60 mm Hg. This removal was independent of the blood flow rate in the range of 100-300 ml/min. In studies in vitro, disturbances in blood electrolytes were compensated for by the selection of the appropriate composition of the dialysate fluid.

Carbon Dioxide↗
PubMedDate not supplied

Evaluation of eluents from separations of CD34+ cells from human cord blood using a commercial, immunomagnetic cell separation system.

Human CD34+ cells from cord blood were separated in a two-step process using a commercial, immunomagnetic cell retention system. The performance of the system was evaluated by analyzing a number of eluents from the separations with a number of analytical techniques. In addition to cell counts and flow cytometry analysis, a new experimental technique that is undergoing development, cell tracking velocimetry (CTV), was used. CTV measures the degree to which a cell is immunomagnetically labeled, known as the magnetophoretic mobility, of a population of cells on a cell-by-cell basis and presents the results in the form of a histogram similar to flow cytometry data. The average recovery and purity of CD34+ cells from 10 separations was 52% and 60%, respectively. CTV analysis indicated that the mean magnetophoretic mobility of the positively enriched CD34 cells was 9.64 x 10(-5) mm3/T-A-s, while the mean mobility from negative eluents was -2.02 x 10(-6) mm3/T-A-s, very similar to the mobility of unlabeled cells. Within the positive eluents, the range of magnetophoretic mobility was approximately 50-fold, representing a plausible 50-fold range in surface CD34 antigen expression. CTV analysis also indicated that in some separations, positive cells were not retained by the immunomagnetic cell retention system. Finally, preliminary studies indicate that monocytes might be a primary cause in the lower purities and recoveries seen in this study. It is suggested that the monocytes phagocytose the magnetic nanobeads and become sufficiently magnetized to be retained within the Miltenyi column, reducing the purity of the positive eluent.

Antigens, CD34↗