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PubMedDate not supplied

Contamination control in nursing with filtration. Part 1: filters applied to intravenous fluids and point-of-use hospital water.

Filters often are viewed as screens with openings smaller than the particles intended to be removed by a process technically known as direct interception. However, filter manufacturing embraces far more advanced technological approaches, with an evolution toward selective removal of cells or soluble constituents from complex physiologic solutions. An appreciation of filtration development makes it easy to understand how differently manufactured filters with the same claims may not perform identically. This article focuses on the filtration of intravenous solutions and point-of-use hospital water.

Biological Availability↗
PubMed2002

Development of a combined filtration-enrichment culture followed by a one-step duplex PCR technique for the rapid detection of Campylobacter jejuni and C. coli in human faecal samples.

A new combined filtration-enrichment culture followed by a PCR technique for the rapid detection of Campylobacterjejuni and C. coli in human faeces has been developed. Only bacteria that passed through the membrane could multiply in the enrichment culture; target bacteria were detected by a one-step duplex PCR technique with combinations of primers that are specific for different Campylobacter spp., which should allow for the detection of a mixed infection in a single patient. A Falcon cell-culture insert and 24-well tissue-culture plates were used. After 2 days, both C. jejuni and C. coli were reliably detected in diluted faeces that were seeded with as few as 10 cells which corresponds to a concentration of 10(3) cfu/g. Even allowing for the dilution of faecal samples, this represents an increase in sensitivity of two-to-three orders of magnitude over the conventional filtration method.

Campylobacter coli↗
PubMed1991

Purification of Chlamydia trachomatis by a simple and rapid filtration method.

A simple method for filter purification of Chlamydia trachomatis from cell culture is described. Crude homogenates of chlamydiae-infected cells were passed through a glass prefilter and a 0.6 microns pore diameter polycarbonate filter. The filtrate was then passed through a 0.2 microns pore diameter filter on which the chlamydiae were trapped. This filter was then back-washed to collect the organisms. These procedures removed cell debris and soluble protein, and yielded particles with a narrow size distribution. The mean yield of viable chlamydiae purified by filtration was 64% when the filters were washed at each stage of the process.

Bacteriological Techniques↗
PubMed2006

Detection of antibodies against Mycobacterium leprae culture filtrate protein-10 in leprosy patients.

The prevalence of IgG antibodies against Mycobacterium leprae recombinant culture filtrate protein-10 (rCFP-10) was investigated in serum samples from 56 leprosy patients, 15 tuberculosis (TB) patients, 14 other skin-diseased patients and 20 healthy subjects. On classifying the patients into bacterial index (BI)-positive and BI-negative groups, the assay showed 83.3 % (15/18) sensitivity for detection of BI-positive leprosy patients. On the other hand, the sensitivity for detection of BI-negative patients was 18.4 % (7/38). None of the 15 TB patients and 14 other skin-diseased patients was positive; however, only one out of 20 healthy individuals was positive, indicating that antibody response to culture filtrate protein-10 (CFP-10) was highly specific (98.0 %; 48/49). Statistically, the performance of the CFP-10-based assay was found to be comparable (P>0.05) with that of an anti-phenolic glycolipid-I (PGL-I) antibody-detecting assay. Thus, M. leprae CFP-10 is potentially a specific antigen for measuring antibody response in BI-positive leprosy patients. Being a secreted antigen, CFP-10 may act as a marker for the viability of M. leprae inside the host, and hence its serological potential is worth exploring for application in monitoring the response of patients with BI-positive leprosy (a highly infectious form) during the course of chemotherapy. When comparing the bacteriological and serological results, an agreement of 82.1 % showed that seropositivity to M. leprae CFP-10 corresponded well with bacteriological criteria. Hence, CFP-10 seems to be a suitable antigen for classification of leprosy patients into BI-positive and BI-negative groups.

Ambulatory Care Facilities↗
PubMed1977

Membrane filtration in microscopical examination of urinary sediment.

Microscopical examination of the urinary sediment has been performed after membrane filtration and after routine centrifugation, and the results were compared. Various quantities of urine were filtered through a membrane with pore size of 3 micrometer, stained with Shorr stain and made translucent with xylol. All granular and cellular casts were counted on a trimmed membrane, 15 X 20 mm. The routine centrifugation was carried out on 10 ml urine at 1500 rpm for 3 min. Among 11 patients with glomerulonephrits and recurrent hematuria, casts were found in 9 after filtration but in only 2 after routine centrifugation. Casts were detected by the filter method in the urine after angiography of the kidneys in 8 of 12 patients, after centrifugation in only one of them. No casts were found in 6 patients with hematuria due to urological disorders and in 21 healthy persons. The diagnostic sensitivity of microscopical examination of urine was greatly increased by the filter method. This may be due to larger amount of urine examined by the filter method, but an additional cause may be that routine centrifugation destroys red cell casts.

Adolescent↗
PubMed2004

Development and evaluation of a rapid flow-through immuno filtration test using recombinant filarial antigen for diagnosis of brugian and bancroftian filariasis.

There is an imperative need to develop a rapid antibody test that can be used for diagnosis of clinical cases in travelers and expatriates, primary surveillance in areas of unknown endemicity, detection of early infection in childhood and for monitoring chemotherapeutic programs. A rapid-format, simple and qualitative flow through immuno filtration test has been developed for the identification of total IgG antibodies to recombinant filarial antigen WbSXP-1. This test system employs colloidal gold-protein A reagent as the antibody capture reagent. The sensitivity and specificity of the test was evaluated in a total of 1,230 serum samples. The sensitivity of the test was found to be 90.8% with brugian (n = 70) and 91.4% with bancroftian (n = 140) microfilaraemic subjects. The test showed minimum reactivity (4/10) with Loa loa microfilaria (MF) positive sera and no reactivity (0/20) with Onchocerca MF positive sera. This rapid diagnosis is found to be non-reactive with individuals having other parasitic diseases including schistosomiasis (n = 10), soil-transmitted helminthiases (n = 34) and protozoan infections (n = 33) indicating the potential of this test as a prospective method of diagnosis for both brugian and bancroftian lymphatic filariasis. Stability kinetics was studied at different temperatures and different time periods. The rapid flow-through immuno filtration test is advantageous since it can be stored at room temperature, is user friendly and is particularly applicable in the field as an initial screening method, for epidemiological monitoring of filarial infections in bancroftian and brugian endemic regions of the world.

Animals↗
PubMed1981

Blood pressure, body fluid volumes and glomerular filtration rate during treatment with labetalol in essential hypertension.

1 In a single blind study seventeen patients with mild or moderate essential hypertension and normal renal function were treated with labetalol alone in increasing doses from 300 via 600 to 1200 mg daily. 2 Average supine BP (systolic/diastolic) was reduced by 24/19 mm Hg. Seven patients attained a diastolic BP less than or equal to Hg. A significant postural fall in systolic BP was recorded, but no symptomatic orthostatic hypotension occurred. 3 In twelve patients measurements of plasma volume (125I-albumin), extracellular volume (82Br-space) and glomerular filtration rate (51Cr-EDTA clearance) on placebo and subsequently labetalol showed no systemic changes. 4 Side effects were few causing two withdrawals because of impotence and arthralgia. 5 It is concluded that monotherapy with labetalol results in clinically relevant, persistent and dose dependent reduction in BP in patients with mild or moderate essential hypertension, apparently without concomitant expansion of body fluid volumes or influence on glomerular filtration rate.

Adult↗
PubMed1976

A convenient and reproducible filtration technique for the determination of erythrocyte flexibility.

A micro-cell filtration technique is described in which a silver membrane of 3 mum porosity is used. The apparatus consists of a membrane holder and disposable syringe only. A regeneration procedure which allows indefinite re-use of one membrane is described. Filtration proceeds under the hydrostatic pressure of the fluid column only. A locke-albumin solution has been developed as a suspension medium and adapted for cell washing by the addition of fibrinogen and cholesterol. A plot of the volumes of cells filtered against log time shows a linear relationship for normal erythrocytes. The filtered red cells are virtually undamaged. The overall precision of the method of the order of +/-2%.

Cell Membrane↗
PubMed1980

Evaluation and modification of whole blood filtration in the measurement of erythrocyte deformability in pregnancy and the newborn.

This study was designed to investigate the deformability of erythrocytes from pregnant women and full-term newborn infants, with healthy female adults as a comparison, using a whole blood filtration method. Delay in measurement, white cells, haematocrit, plasma viscosity, temperature and pH all significantly affected the rate of whole blood filtration and could thereby obscure or exaggerate changes in erythrocyte deformability. A new method was developed which eliminated or minimized these sources of error and the study was completed. Fetal erythrocytes were found to be significantly less deformable than adult erythrocytes which were in turn found to be significantly less deformable than erythrocytes from pregnant women. These differences appear to be related to the varying plasma fibrinogen concentrations in the three groups of subjects. The significance of these findings in the special haemodynamic situations found in the neonate and during pregnancy are discussed.

Adult↗
PubMed1993

The effect of filtration on the cellular components in bronchoalveolar lavage fluid.

The effect of filtration through two layers of cotton gauze on the cellular composition of bronchoalveolar lavage (BAL) fluid was studied in 25 patients with pulmonary disease. There was no significant difference between median total cell count in unfiltered and filtered BAL (P = 0.73) or in the distribution of neutrophils or eosinophils. The percentage of bronchial epithelial cells was significantly higher in unfiltered than in filtered BAL (P = 0.02). Furthermore, differential cell counts showed a significantly lower percentage of alveolar macrophages (P = 0.04), and a significantly higher percentage of lymphocytes (P = 0.04) in unfiltered compared with filtered BAL. Thus, gauze filtration results in a loss of bronchial epithelial cells and lymphocytes, and is not recommended in the routine analysis of cellular components in BAL fluid.

Adult↗
PubMed1992

Increase of glomerular filtration rate and renal plasma flow by insulin-like growth factor-I during euglycaemic clamping in anaesthetized rats.

Renal function was studied in anaesthetized rats receiving i.v. infusions of recombinant human insulin-like growth factor-I (IGF-I) under euglycaemic clamp conditions. IGF-I increased glomerular filtration rate up to 35% and renal plasma flow up to 100%, this increase being dose dependent with half-maximal stimulation at serum IGF-I concentrations of about 24 pmol ml-1. Renal vascular resistance was reduced up to 50%, filtration fraction decreased up to 30% and urine flow increased up to three fold while arterial blood pressure was unchanged. Renal haemodynamics were affected at serum IGF-I concentrations that did not stimulate total body glucose disposal during euglycaemic clamping. IGF-I seemed to regulate renal function through IGF-I receptors apparently independent of acute changes of glucose metabolism.

Animals↗
PubMed2006

Filtration, haze and foam characteristics of fermented wort mediated by yeast strain.

AIMS: To investigate the influence of the choice of yeast strain on the haze, shelf life, filterability and foam quality characteristics of fermented products. METHODS AND RESULTS: Twelve strains were used to ferment a chemically defined wort and hopped ale or stout wort. Fermented products were assessed for foam using the Rudin apparatus, and filterability and haze characteristics using the European Brewing Convention methods, to reveal differences in these parameters as a consequence of the choice of yeast strain and growth medium. CONCLUSIONS: Under the conditions used, the choice of strain of Saccharomyces cerevisiae effecting the primary fermentation has an impact on all of the parameters investigated, most notably when the fermentation medium is devoid of macromolecular material. SIGNIFICANCE AND IMPACT OF THE STUDY: The filtration of fermented products has a large cost implication for many brewers and wine makers, and the haze of the resulting filtrate is a key quality criterion. Also of importance to the quality of beer and some wines is the foaming and head retention of these beverages. The foam characteristics, filterability and potential for haze formation in a fermented product have long been known to be dependant on the raw materials used, as well as other production parameters. The choice of Saccharomyces cerevisiae strain used to ferment has itself been shown here to influence these parameters.

Beer↗
PubMed1990

Cigarette smoking and glomerular filtration rate in insulin-treated diabetics without manifest nephropathy.

A sample of 120 insulin-treated diabetics, 20-40 years of age, with a glomerular filtration rate (GFR) exceeding -2 SD of the age-adjusted value and without albuminuria greater than 300 mg 24 h-1, and with a diastolic blood pressure not greater than 90 mmHg, were studied in order to evaluate the possible effect of smoking on glomerular filtration rate. The patients reported their smoking habits, use of oral snuff, use of alcohol, physical exercise and heredity for hypertension in a simple questionnaire. GFR was assessed with 51Cr-EDTA-clearance and glomerular hyperfiltration was defined as a value exceeding +2 SD of the age-adjusted normal value. We found a significantly higher prevalence of glomerular hyperfiltration in smokers than in non-smokers (41% vs. 18%), but no increased prevalence in users of oral snuff. In cigarette smokers a multivariate analysis revealed that GFR was positively related to body mass index (BMI), and negatively related to the number of cigarettes smoked per week and the mean blood pressure. In non-smokers GFR was dependent only on age. We conclude that in insulin-treated diabetics glomerular hyperfiltration is related to smoking, and that the GFR in smoking diabetics is directly dependent on the smoke doses. As glomerular hyperfiltration is regarded as a risk factor for diabetic nephropathy, our findings should be relevant to preventive measures in clinical work.

Adult↗
PubMed1976

Studies on new process procedures in plasma fractionation and industrial scale. III. Removal of precipitates by filtration through a horizontal leaf filter with centrifugal cleaning (Funda filter) as an alternative to tubular-bowl centrifuges.

The possibilities for replacing the time-consuming and labor-intensive centrifugation step in the plasma fractionation process with a filtration technique using filter aids were explored using a Funda filter (pat. Dr. Ing. Hans Müller). The filtration technique proved effective in the separation of the impure plasma fractions. On the other hand, its use in the separation of pure albumin and gamma-globulin fractions appears doubtful.

Centrifugation↗
PubMed1989

A novel method for removal of human immunodeficiency virus: filtration with porous polymeric membranes.

We propose a new method to rid solutions of a virus by using a novel regenerated multilayered structured cellulose membrane (BMM). When the filtrate of human immunodeficiency virus (HIV) preparation was obtained through BMM it showed no infectivity. Electron microscopic observation revealed that HIV was completely caught by the multilayers of the BMM. Conveniently, BMM was seldomly found to adsorb protein molecules and also to have a high filtration rate. These characteristics may have a use in the removal of other variously sized pathogenic agents from plasma.

Cells, Cultured↗
PubMed1989

Storage of leukocyte-poor red cell concentrates: filtration in a closed system using a sterile connection device.

Storage of leukocyte-poor red cell concentrates (LP-RCC) was investigated after filtration in a closed system that was assembled using a Sterile Connection Device (SCD). The LP-RCC were stored for up to 6 weeks following filtration with either 0.9% saline solution (n = 14) or saline-adenine-glucose-mannitol (SAG M) solution (n = 15) to prime and rinse the cellulose acetate filter. The results were compared with the data of nonfiltered buffy-coat-poor red cell concentrates (BC-poor RCC) stored in SAG M solution (n = 10). All LP-RCC contained less than 10(6) leukocytes whereas the nonfiltered BC-poor RCC contained 675 +/- 286 X 10(6) leukocytes at day 1, decreasing to 83 +/- 49 x 10(6) at day 42. Although glucose consumption, lactic acid production and decrease in pH was similar from day 7 through 28 in both groups of LP-RCC, a significantly steeper decline of ATP values as well as a higher hemolysis and LDH release was observed in the LP-RCC filtered with saline. During storage of the nonfiltered BC-poor RCC in SAG M, significantly higher glucose consumption (p less than 0.01), LDH release (p less than 0.001), rate of hemolysis (p less than 0.001) and a lower pH (p less than 0.001) were found, compared to the filtered units. It is postulated that the leukocytes present in the nonfiltered BC-poor RCC were responsible for these differences. The ATP values in the SAG-M-filtered and nonfiltered BC-poor RCC in SAG M were comparable.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine↗
PubMed1990

Comparison of platelet activation and membrane glycoprotein Ib and IIb-IIIa expression after filtration through three different leukocyte removal filters.

We evaluated three filters used for leukocyte removal from platelet concentrates: Imugard IG 500, Pall PL100 and Sepacell PL-10A. Filter performance, platelet activation and expression of membrane glycoproteins Ib and IIb-IIIa were evaluated. Imugard, Pall and Sepacell showed median postfiltration in vitro platelet recoveries of 88, 84 and 80%, and total residual leukocyte counts of 16.1, 7.5 and 0.6 x 10(6)/pool of 8 platelet concentrates, respectively. Mean platelet volume was reduced after filtration with all filters. Postfiltration values of glycoproteins Ib and IIb-IIIa, and of activation markers GMP 140 and gp 53 were not significantly different from prefiltration values. Filtration through Imugard, Pall and Sepacell did not induce significant platelet activation or modifications of platelet membrane glycoproteins Ib and IIb-IIIa.

Cell Separation↗
PubMed1993

Prevalence of platelet transfusion reactions before and after implementation of leukocyte-depleted platelet concentrates by filtration.

To determine the impact of platelet leukodepletion by filtration on the overall prevalence of reported transfusion reactions associated with platelet concentrates, we audited platelet transfusion reactions after infusion of platelet concentrates reported at University Hospitals of Cleveland over 6 months before (interval 1, July 1, 1989 to December 31, 1989) and after (interval 2, July 1, 1990 to December 31, 1990) implementation of the Pall PL 50 filter on our adult Hematology-Oncology inpatient unit (Division 60). Thirty-two (1.7%) of 1,901 random, pooled platelet transfusion events resulted in blood bank transfusion reaction workups in interval 1, compared to 90 (5.3%) of 1,704 in interval 2 (p < 0.001). The Division 60 service accounted for more of our hospital-wide platelet reactions after implementation of the filter in interval 2 (84%) than before filtration in interval 1 (42%), p = 0.002. The prevalence of reaction workups for Division 60 was 0.6% for interval 1, compared to 4.3% for interval 2 (p < 0.001). No differences were found between interval 1 and interval 2 for the rate of discontinuation of platelet transfusion (36 vs. 32%, p = 0.14), rate of premedication for platelet transfusion (72 vs. 65%, p = 0.6), percentage of direct antiglobulin test-positive reactions (17 vs. 5.4%, p = 0.09), percentage showing icteric/hemolyzed serum (15 vs. 4.4%, p = 0.09), or reactions believed to be due to red blood cell incompatibility (8.8 vs. 1.1%, p = 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)

ABO Blood-Group System↗