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PubMed1989

[Kinetics of lipids and lipoproteins with determination of the recovery rate in the non-steady state following plasma, membrane filtration and dextran sulfate adsorption apheresis in hypercholesterolemia].

In the work presented here, the efficiency of the following techniques was determined in the period 1983-1988 with respect to the elimination of lipids, lipoproteins and apoproteins in patients with severe hypercholesterolemia; firstly with plasmapheresis, then with membrane-filtration apheresis, and recently with dextran sulfate adsorption apheresis. Furthermore, the loss resulting from removal by apheresis in lipids, lipoproteins and apoproteins was calculated by means of a single-compartment model from pool size and recovery rates. It could be shown that the individual lipids (TG, CH, LDL-CH, P) in the serum as well as in the lipoprotein fractions (VLDL, LDL, HDL) attained new steady states at differing rates, the recovery times for cholesterol being the longest, those of HDL-CH and apoproteins AI, AII, CII, CIII and E the shortest. The absolute replacement in "mg/kg BW/d" was 35 for beta-lipoprotein, 18-22 for total-CH, 13-17 for LDL-CH, 10-12 for apoprotein B; for the antiatherogenic lipids HDL-CH it was 1.72-2.7 mg/kg BW/d; for alpha-lipoprotein 14-23 mg/kg BW/d; for apoprotein HDL 16-19 mg/kg BW/d. The recovery rates for anti- and atherogenic lipids for women with heterozygous FH were higher than for men with FH. Rates of 0.235; 0.510 and 0.183 mg/kg BW/d were measured for CII, CIII and apoprotein E respectively. Dextran sulphate adsorption apheresis (Kaneka) is a more specific method for eliminating LDL-CH and apoprotein B than plasmapheresis and membrane filtration apheresis. The amounts removed in LDL and apo B with the Kaneka technique are largely identical with those taken out by membrane filtration. Larger relative and absolute recovery rates for LDL-CH, total-CH and apo B were found after Kaneka's DSA-apheresis, which may be explained by the more specific removal in LDL-CH and apo B.

Blood Component Removal↗
PubMed1975

A combined adsorption-gel filtration technique for the determination of the cortisol-binding capacity of transcortin.

A combined adsorption-gel filtration technique has been developed for the quantitation of the cortisol-binding capacity of transcortin: Endogenous steroids are removed from plasma by adsorption on uncoated charcoal. Saturation of the "stripped" binding sites of transcortin is accomplished by equilibrating the sample with a definite amount of labeled cortisol of low specific activity (0.1 muCi/mug). Transcortin-bound [4-14C]cortisol is isolated by gel filtration over Sephadex G-50 at 4 degrees C and measured by liquid scintillation counting. The cortisol-binding capacity of transcortin is calculated directly on the basis of the known specific activity of cortisol. The modification described eliminates methodological disadvantages associated with the original gel filtration procedures, i.e. the possible interference of various endogenous steroids with cortisol binding to transcortin, and the necessity of fluorometric or colorimetric determination of protein-bound cortisol. The values of the cortisol-binding capacity of transcortin in plasma obteined by this simplified assay are in close agreement with results reported in the literature (mean +/- S.D.): healthy males 261 +/- 23 mug/l) of transcortin-bound cortisol (n = 13), healthy nonpregnant females 255 +/- 31 mug/l (n = 15), and pregnant females prior to delivery 560 +/- 82 mug/l (n = 12).

Adsorption↗
PubMed1991

Comparison of acid ethanol extraction and acid gel filtration prior to IGF-I and IGF-II radioimmunoassays: improvement of determinations in acid ethanol extracts by the use of truncated IGF-I as radioligand.

Insulin-like growth factor binding proteins interfere in the IGF-I and -II radioimmunoassays. In an attempt to overcome this problem, we have compared the use of truncated IGF-I, with reduced IGFBP affinity, and IGF-I as radioligands for IGF-I RIA measurements in serum separated by acid gel filtration or acid ethanol extraction followed by cryo-precipitation. With truncated IGF-I as radioligand the IGF-I measurements in acid gel filtrates and acid ethanol extracts were significantly correlated in healthy subjects (N = 42, r = 0.91, p less than 0.001) and in patients with acromegaly (N = 10, r = 0.85, p less than 0.01), GH deficiency (N = 10, r = 0.88, p less than 0.001) or Type I diabetes mellitus (N = 10, r = 0.90, p less than 0.001). In contrast, the IGF-I concentrations in acid ethanol extracts determined with IGF-I as radioligand did not correlate with those in acid gel filtrates using truncated IGF-I radioligand in patients with acromegaly (r = 0.61, NS) or GH deficiency (r = 0.46, NS). In the latter group the mean IGF-I concentrations measured in acid ethanol extracts were erroneously elevated by 112%. Low-affinity antibodies used for IGF-II RIA determinations failed to give reliable results in acid ethanol extracts from patients with Type I diabetes mellitus or GH deficiency. In conclusion, erroneously high IGF-I concentrations owing to binding of the radioligand to IGFBPs not completely removed by acid ethanol extraction can be avoided by the use of truncated IGF-I as radioligand.

Acromegaly↗
PubMed2004

Patterns of referral for inferior vena caval filtration: delays and their impact.

OBJECTIVE: We sought to study the referral patterns for inferior vena caval filtration and explore the relationship between delays in filter insertion and clinical outcomes. MATERIALS AND METHODS: We retrospectively reviewed 101 consecutive inferior vena caval filters inserted in 101 patients in a university hospital between the June 2000 and July 2001. A time line was created listing the time of diagnosis of deep venous thrombosis or pulmonary embolism, contraindication or complication of anticoagulation therapy, and time of insertion of inferior vena caval filter. RESULTS: The average elapsed time between the clinical indication for caval filtration and filter placement in all patients was 1.64 days (range, 0-17 days). Two patients (2%) sustained pulmonary emboli after being diagnosed with deep venous thrombosis before receiving a filter. The lengths of time between filter indication and insertion for these patients were 2 and 8 days. CONCLUSION: In our hospital, there are wide variations in perceived urgency of vena caval filtration. In two patients, delays longer than 24 hr between indication and insertion of inferior vena caval filters resulted in symptomatic pulmonary emboli.

Adult↗
PubMed2005

Cytokine response of bovine mammary gland epithelial cells to Escherichia coli, coliform culture filtrate, or lipopolysaccharide.

OBJECTIVE: To define the cytokine response of a cultured mammary gland epithelial cell line (ie, Mac-T) when incubated with Escherichia coli or its products. SAMPLE POPULATION: Mac-T cells and E coli from cows with mastitis. PROCEDURE: Mac-T cells were incubated with E coli or its products. The cytokine response of Mac-T cells to these treatments was quantified by measuring mRNA content of interleukin (IL)-1alpha, IL-1beta, IL-8, and tumor necrosis factor (TNF)-alpha by use of a quantitative reverse transcriptase-polymerase chain reaction assay. The amount of TNF-alpha secreted was also measured. RESULTS: Treatment with E coli or its products resulted in significant increases in IL-1alpha, IL-8, and TNF-alpha mRNA content in Mac-T cells. This increase was reversible when culture filtrate was incubated with polymyxin B. The amount of IL-1beta mRNA in Mac-T cells increased only slightly over baseline after treatment with E coli or its products, but this increase was not diminished by incubation of E coli filtrate with polymyxin B. CONCLUSIONS AND CLINICAL RELEVANCE: Incubation of Mac-T cells with E coli or its products resulted in increased amounts of IL1alpha, IL-8, and TNF-alpha mRNA. Inhibition of this response by incubation of culture filtrate with polymyxin B suggested that lipopolysaccharide was the main bacterial product that stimulated the cytokine response. The small increase in IL-1beta content in Mac-T cells incubated with E coli or its products suggested that this cytokine had a smaller role in the Mac-T cell response to E coli.

Animals↗
PubMed1984

The effects of intestinal Escherichia coli 263, intravenous infusion of Escherichia coli 263 culture filtrate and iron dextran supplementation on iron metabolism in the young pig.

An experiment using 32 pigs in a 2(3) factorial arrangement of treatments was used to determine the effects on the (1) level of iron dextran supplementation, (2) iv infusion of an Escherichia coli 263 culture filtrate and (3) presence of E. coli 263 in a ligated intestinal segment, on the ability of the young pig to limit systemic Fe availability. Iron dextran was administered im 3 d postpartum. Culture filtrate was infused iv, E. coli were injected into ligated intestines and blood sampling was started at 14 d postpartum. Blood was taken every 2 h for 22 h, after which pigs were euthanized and livers, spleens and kidneys were removed. Pigs receiving 400 mg of iron dextran (HiFe) exhibited greater serum Fe (SFe) and lower total Fe-binding capacity (TIBC) than pigs injected with 100 mg Fe (LoFe). The effects of the E. coli culture filtrate infusion appeared to be associated with endotoxin-induced circulatory shock. The presence of E. coli in the intestine increased TIBC in LoFe pigs, but not in HiFe pigs. The increase in TIBC coincided with the time of maximal fluid secretion into the intestine. Intestinal E. coli also caused an increase in liver Fe content, particularly in HiFe pigs. These data suggest that intestinal E. coli can cause a shift of Fe from the plasma to the reticuloendothelial system, and pigs receiving high supplemental dosages of Fe are less able to limit the availability of Fe to microorganisms.

Animals↗
PubMed1981

Erythrocyte filtration and smoking.

Erythrocyte filterability may be influenced by 'acute' smoking with subsequent changes of RBC filterability and by chronic inhalation of cigarette smoke which may lead to chronic alterations. To evaluate chronic alterations of RBC deformability we compared the erythrocyte filtration rates of 60 young, healthy chronic smokers (30 female, 30 male) with those of 60 young, healthy non-smokers (again 30 female and 30 male). The comparison showed a higher filtration rate in the male non-smokers group than in the group of the male smokers, the difference however was not statistically significant. Female smokers and non-smokers did not show any noticeable difference in their RBC filtration rates.

Adolescent↗
PubMed1994

Enhancement of filtration surgery with cytosine arabinoside and reversal of toxicity with 2'-deoxycytidine.

Antifibrosis agents have improved the success of glaucoma filtration surgery, although undesired side effects are not readily reversible and may present a major limitation in the use of these agents. Our purpose was to study the efficacy of cytosine arabinoside (Ara-C) as an adjunctive antimetabolite in glaucoma surgery in the rabbit, and reversal of toxicity due to this agent with the competitive inhibitor 2'-deoxycytidine. Posterior lip sclerectomy was performed in rabbit eyes treated with 15 mg subconjunctival Ara-C daily for 7 d then every other day for 7 d. Mean intraocular pressure was lower in eyes treated with Ara-C compared with controls at all time points following filtration surgery. On the 10th postoperative day, the mean intraocular pressure of control eyes (25.0 +/- 1.9 mm Hg) had returned to baseline levels, whereas the intraocular pressure of eyes treated with Ara-C was significantly lower (16.0 +/- 1.7 mm Hg) (P < 0.001). Bleb survival was also prolonged in the Ara-C-treated eyes. The major ocular side effect of Ara-C was corneal toxicity, with epithelial defects in 40% of eyes after 8 daily injections of 15 mg Ara-C. Reversal of toxicity was enhanced with 2'-deoxycytidine, with complete resolution of epithelial toxicity after 6.5 +/- 1.7 d following daily topical 10% 2'-deoxycytidine compared with 12.7 +/- 0.58 for control (P < 0.002). These results demonstrate that postoperative subconjunctival injection of Ara-C results in improved bleb function after filtration surgery in the rabbit. Recovery from corneal epithelial toxicity due to Ara-C is markedly enhanced with the competitive inhibitor 2'-deoxycytidine.

Animals↗
PubMed1994

The mean filtration pressure of leukocyte suspensions and its relation to the passage of leukocytes through nuclepore filters and capillary networks.

OBJECTIVE: To quantitatively evaluate the deformability of bulk suspensions of leukocytes (WBCs), account for the variance of individual cell mechanical properties, and deduce the potential for WBC entrapment within the capillary network in response to alterations in cell properties. METHODS: The transient washout of WBCs initially trapped under low perfusion pressure in 5-microns pores of Nuclepore filters was analyzed for a 0.2-ml bolus of WBCs (derived from hamsters) with equal numbers of filter pores and cells, to characterize the statistical distribution of pressures, Pyield, required to dislodge the cells. Contributions of the variance in WBC diameter, pore diameter, and cremaster muscle capillary diameter to Pyield were estimated with a WBC cortical shell model and an analysis of the probability function of the ratio of WBC to pore diameter, lambda. RESULTS: For normal WBCs, Pyield exhibited a log-normal distribution with mean (Pyield) of 0.59 cmH2O. Incubation of cells in cytochalasin-B reduced (Pyield) almost 50%, whereas phorbol myristate acetate increased (Pyield) twofold. Incubation in N-formyl-methiolnyl-leucyl-phenylalanine had no significant effect on (Pyield), as polymorphonuclear cells became permanently trapped in the filter. The fluorescent dyes acridine orange, acridine red, and tetramethylrhodamine isothiocyanate increased (Pyield) as much as 10-fold, whereas steady-flow filtration methods showed no alteration. Analysis of the distribution of lambda revealed that due to their smaller pore diameters, in vitro filtration methods may overestimate in vivo values of (Pyield) by almost twofold. CONCLUSIONS: The transient filtration of WBC suspensions appears to be much more sensitive to subtle alterations in WBC deformability than steady-flow methods and may provide greater insight into the determinants of capillary perfusion. Estimates of (Pyield) are comparable to those obtained with micropipettes and permit analysis of substantially greater numbers of cells within a sample. Fluorescence labeling techniques should be used with caution, as they may dramatically alter cell properties to an extent undetectable by direct in vivo observations.

Animals↗
PubMed1989

Soluble complex formation of bovine immunoglobulin G2 with staphylococcal protein A studied by gel filtration chromatography.

The binding property of bovine IgG2 to staphylococcal Protein A was investigated by the methods of gel filtration chromatography and affinity chromatography. High performance gel filtration chromatography was carried out using TSK gel G3000SW and G2000SW columns, and immobilized Protein A column was used for affinity chromatography. Although bovine IgG2 did not form any precipitin lines with Protein A by double diffusion method on agar gel, IgG2 could bind to immobilized Protein A column. Moreover, by gel filtration chromatography, peaks of the complex between bovine IgG2 and Protein A were observed in addition to the IgG2 monomer peak. Thus, it is concluded that bovine IgG2 interacts with staphylococcal Protein A and forms "soluble complexes". Carbethoxylated IgG2 lost its affinity to Protein A indicating that histidyl residues in IgG2 is essential for the binding to Protein A.

Animals↗
PubMed2005

Sporadic cryptosporidiosis decline after membrane filtration of public water supplies, England, 1996-2002.

The incidence of sporadic cryptosporidiosis among 106,000 residents of 2 local government districts in northwest England before and after installation of membrane filtration of public water supplies was compared to that of 59,700 residents whose public water supplies remained unchanged. A national outbreak of foot and mouth disease in livestock during 2001 was associated with a decline in sporadic human cryptosporidiosis in all regions of the United Kingdom. In a Poisson regression model, membrane filtration was associated with an estimated 79% reduction (incidence ratio 0.207, 95% confidence intervals 0.099-0.431, p < 0.0001) after adjustment for the interval of the foot and mouth disease epidemic and the water source. Despite the confounding effect of that epidemic, membrane filtration of the public water supply was effective in reducing the risk for sporadic human Cryptosporidium infection in this population.

Adolescent↗
PubMed1983

Theoretical modeling of filtration of blood cell suspensions.

A theoretical model of filtration of suspensions containing red blood cells (RBCs) and white blood cells (WBCs) has been developed. Equations are written for the pressure drop, the filtration flow and the fractions of filter pores containing RBCs (alpha) and WBCs (alpha*). Because the relative resistances (ratios of resistance of cell to resistance of suspending fluid) of RBCs (beta) and WBCs (beta*) through the filter pore are greater than one, the transit of these cells (especially WBCs) through the filter is slower than that of suspending fluid; this leads to values of alpha and alpha* higher than those simply expected from the hematocrit and leukocrit, respectively, in the entering and exiting suspensions. In the absence of pore plugging by the cells (steady flow), the pressure drop can be computed from alpha, alpha*, beta and beta*. In order to model unsteady flow, differential equations are written to include pore plugging and the subsequent unplugging by the rising filtration pressure at a constant flow. By specifying the fractions of entering RBCs (epsilon) and WBCs (epsilon*) which would plug the pores and the rate at which the plugged pores would unplug in response to pressure rise (epsilon u), as well as the fractions of entering RBCs (epsilon p) and WBCs (epsilon p*) that would plug the pores permanently, theoretical pressure-time curves can be generated by numerical integration, and the results fit the experimental data well. From such fitting of theoretical curve to experimental data, information can be deduced for epsilon, epsilon*, epsilon u, epsilon p and epsilon* p.

Erythrocytes↗
PubMed1984

Filtration pressure and red blood cell deformability: evaluation of a new device: erythrometre.

The authors have tested a new device that records the filtration pressure of a suspension of red blood cells (R.B.C.) passing through a 3 micron pore diameter filter. As the flow rate is constant, the pressure increase allows to appreciate an index of the R.B.C. deformability. In order to test the performances of this new equipment, the authors have studied the influence of the variation of the following parameters. Haematocrit from 0.5 to 2%, Buffer composition; time elapsing from drawing to measurement: from hour 0 to hour 3. This analysis has been performed on donors; on packed red cells preserved in CPD, from D0 to D21 and on patients specimens and the results have been compared to the whole blood filtration according to the Reid and Dormandy method. The following parameters were simultaniously measured: Whole blood viscosity by means of a Low Shear 30 viscosimeter, Intraerythrocyte ATP by bioluminescence, Membrane lipid composition (cholesterol, phospholipids), Scanning electron microscopy. This new apparatus, measuring the filtration pressure seems to be a more sensitive and reproductible method allowing to approach the RBC deformability, and quite usefull in clinical haemorheology.

Erythrocytes↗
PubMed1991

Plasma fractionation by dead-end membrane filtration: effects of membrane properties and plasma flux.

Plasma fractionation by membrane filtration permits the reinfusion of the patient with his own albumin. In this study, the influence of membrane nature and plasma flux on plasma fractionation in dead-end mode is investigated with acetate hollow fiber filters. It is found that transmembrane pressure TMP rises exponentially with time, the rate of increase being proportional to plasma flux. The faster TMP rises, the faster the drop in sieving coefficient SC. It is also found that albumin SC is a function of TMP and not of plasma flux. Theoretical analysis of the dead-end filtration was performed. This theoretical model indicates that the observed variation of TMP with time is consistent with the assumptions that pore volume decreases proportionally to the filtrate plasma volume.

Blood Component Removal↗
PubMedDate not supplied

Subconjunctival placement of human amniotic membrane during high risk glaucoma filtration surgery.

BACKGROUND AND OBJECTIVE: To determine whether subconjunctival placement of amniotic membrane improves filtration results in patients with glaucoma at high risk for surgical failure. PATIENTS AND METHODS: Retrospective review of 17 eyes of 15 patients who had amniotic membrane applied during glaucoma surgery with or without mitomycin C or 5-fluorouracil. RESULTS: Mean intraocular pressure decreased from 27.0 +/- 9.1 mm Hg preoperatively to 18.1 +/- 11.0 mm Hg postoperatively with a mean follow-up of 179 days. Complications included self-limited conjunctival wound dehiscence (n = 5), uveitis recurrence (n = 2), and cataract progression (n = 1). CONCLUSIONS: The results suggest that subconjunctival placement of amniotic membrane may improve filtration outcome in high risk eyes. It will be of interest to determine whether the anti-inflammatory, anti-angiogenic, and antifibrotic properties of amniotic membrane placed subconjunctivally and under the scleral flap will improve filtration surgery outcome by a prospective, randomized study.

Adolescent↗
PubMedDate not supplied

The use of intravitreal gas for the treatment of ocular hypotony after glaucoma filtration surgery.

Hypotonous maculopathy is a serious complication of glaucoma filtration surgery. A patient with hypotonous maculopathy due to excessive filtration was treated with intravitreal gas. During the next several months, the intraocular pressure increased and the visual acuity improved. Intravitreal gas is useful for the treatment of hypotonous maculopathy due to excessive aqueous filtration.

Aged↗
PubMed1996

Effective isolation of MPB64 from a large volume of culture filtrate of Mycobacterium bovis BCG Tokyo.

MPB64, a secretory protein of Mycobacterium bovis BCG Tokyo, was isolated from a culture filtrate of the bacteria in Sauton synthetic medium harvested on day 8. The protein was isolated by five steps; (i) concentration of the culture filtrate by cutting the molecules smaller than 5 kDa with the Millipore Pellicon Cassette system, (ii) affinity separation by a Phenyl Sepharose CL-4B column, (iii) separation with a DEAE-Sepharose CL-6B column with 3 M urea, (iv) separation with a Sephacryl S200HR column, and (v) separation with a DEAE-Sepharose column without urea. MPB64 in each fraction was determined by comparing the band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with that of standard MPB64. The specificity of isolated MPB64 was tested by immunoblotting with anti-MPB64 antibody. The potency of isolated MPB64 in eliciting skin reaction in the BCG-sensitized guinea pigs was the same to that of standard MPB64. The method described herein is an improved one for isolating MPB64 from a large volume of culture filtrate of M. bovis BCG Tokyo. The technique should be applicable to isolation of other mycobacterial secretory proteins.

Antigens, Bacterial↗
PubMed1999

A slit-lamp needling filtration procedure for uncontrolled glaucoma in pseudophakic and aphakic eyes.

In one aphakic and one pseudophakic patient without previous filtration surgery, a transconjunctival needling procedure similar to that used for failed filtration procedures was performed to create a filtering bleb. In both cases, intraocular pressure was successfully lowered for 6 months until the occurrence of bleb encapsulation, which was relieved by transconjunctival needling. There were no complications. In selected cases, this minimally invasive slit-lamp needling procedure provides successful filtration.

Aged↗