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PubMed1992

Improvement in semen quality and sperm fertilizing ability after filtration through the L4 membrane: comparison of results with swim up technique.

The L4 filtration membrane was used at our laboratory on 30 semen specimens (19 from suspected subfertile patients and 11 from fertile donors) to assess changes in semen quality after routine sperm washing and swim up versus filtration through the L4 membrane. Of these 30 samples 17 (11 suspected subfertile patients and 6 fertile donors) were chosen to evaluate differences in sperm fertilizing ability between the 2 sperm preparation methods. Liquified specimens were analyzed on a Cell Soft semen analyzer. Semen specimens were divided equally, and 1 aliquot was processed by sperm washing and the swim up technique and the other by filtration. In all subjects the results of semen analysis and the hamster-egg penetration test showed significant improvement in sperm quality and fertilizing ability after filtration through the L4 membrane. Sperm motility was 58% after the swim up technique compared to 79% after filtration (p less than 0.0001) and velocity was 47 mu. per second after the swim up method compared to 52 mu. per second after filtration (p less than 0.048). Penetration rate and penetration index also showed a significant increase after filtration over values for the swim up method. Our results demonstrate that sperm filtration through the L4 membrane provides results superior to those of the traditional swim up technique. Due to significant savings in time associated with its use the L4 membrane can be used during sperm processing for intrauterine insemination and in vitro fertilization procedures.

Female↗
PubMed1979

Glomerular filtration dynamics in the dog during elevated plasma colloid osmotic pressure.

To determine if the glomerular filtration coefficient (Kf) of the dog is influenced by changes in plasma colloid osmotic pressure (COP), we conducted micropuncture experiments in dogs given concentrated albumin solutions. In one group (N = 9), filtration dynamics were evaluated following infusion of 450 to 600 ml of a 25% bovine albumin solution. To minimize the effects of acute volume expansion, we also achieved high COP levels in another group (N = 7) by albumin loading on the day prior to the experiment. In all experiments, renal arterial pressure was reduced to approximately 90 mm Hg to minimize potential errors that might lead to overestimation of single nephron filtration rate (SNGFR) and glomerular pressure (GP). In the acutely expanded dogs, COP increased to 23.0 +/- (SEM) 0.9 mm Hg, SNGFR was 59 +/- 6 nl/min, estimated GP was 61.0 +/- 2.0 mm Hg, proximal tubule pressure (PTP) was 23.0 +/- 1.6 mm Hg, and superficial filtration fraction (SFF) was 0.13 +/- 0.02. A similarly reduced whole kidney filtration fraction was also observed, due almost entirely to a marked increase in renal blood flow. When compared to noninfused control dogs (N = 13), Kf was significantly higher in the dogs with elevated COP, being 5.3 +/- 0.6 nl/min/mm Hg as compared to 3.4 +/- 0.3 nl/min/mm Hg. Average effective filtration pressure (EFP) was 12 +/- 1mm Hg, and EFP at the efferent end of the glomerular capillaries was 8.9 +/- 1.2 mm Hg. In the group infused on the prior day, COP was 20.0 +/- 0.8 mm Hg, SFF was 0.26 +/- 0.01, SNGFR was 70 +/-8 nl/min, GP was 59 +/- 2 mm Hg, and PTP was 19.0 +/- 1.5 mm Hg. Average EFP was 15 +/- 1 mm Hg, and EFP at the efferent end of the capillaries was 7.5 +/- 0.7 mm Hg. kf was 4.85 +/- 0.66 nl/min/mm Hg, a value significantly higher than that obtained in control dogs having a COP of 15.0 +/- 0.6 mm Hg. Furthermore, one group of control dogs (N = 4), expanded with an isooncotic albumin solution, did not exhibit significant changes in Kf even though the degree of plasma volume expansion was similar to the group expanded with concentrated albumin solution. These experiments are consistent with previous findings obtained in the rat that Kf is influenced by the COP, although the changes in Kf appear to be less than they are in the rat. The data indicate that even under these conditions of elevated COP, the filtration process in the dog is characterized by positive filtration pressures throughout the length of the glomerular capillaries.

Albumins↗
PubMed1986

Glomerular filtration surface in type I diabetes mellitus.

Previously we have shown that relative glomerular mesangial expansion was an important correlate of renal dysfunction in diabetes. To extend the understanding of structural functional relationships, 37 patients with type I diabetes mellitus for 5 to 33 years were studied with multiple creatinine clearance (Ccr), urinary albumin excretion, and blood pressure measurements, and percutaneous renal biopsies. Glomerular volume and percent sclerosed glomeruli were determined; quantitative stereology was performed to determine relative glomerular structural parameters. Per glomerulus we calculated mesangial volume and capillary filtration surface and per patient we estimated capillary filtration surface. Capillary filtration surface per glomerulus or per patient were highly predictive of Ccr (r = +0.78, r = +0.79, P less than 0.001). There was a significant but weak relationship between Ccr and mesangial volume. However, mesangial volume and glomerular volume together were highly predictive of both Ccr and filtration surface. Mesangial volume was increased and filtration surface decreased in the hypertensive patients and the patients with urinary albumin excretion less than 250 mg/24 hr. Thus, it appears that mesangial expansion within a relatively large glomerulus has less influence on filtration than does a similar increase in mesangial volume within a smaller glomerulus. There is a striking relationship between glomerular filtration rate and filtration surface in diabetes throughout the range from hyperfiltration to significant hypofiltration.

Adolescent↗
PubMed1998

Induction of acid tolerance at neutral pH in log-phase Escherichia coli by medium filtrates from organisms grown at acidic pH.

Escherichia coli grown at pH 5.0 became acid-tolerant (acid-habituated) but, in addition, neutralized medium filtrates from cultures of E. coli grown to log-phase or stationary-phase at pH 5.0 (pH 5.0 filtrates) induced acid tolerance when added to log-phase E. coli growing at pH 7.0. In contrast, filtrates from pH 7.0-grown cultures were ineffective. The pH 5.0 filtrates were inactivated by heating in a boiling water-bath but there was less activity loss at 75 degrees C. Protease also inactivated such filtrates, which suggested that a heat-resistant protein (or proteins) in the filtrates was essential for the induction of acid tolerance. Filtrates from cells grown at pH 5.0 plus phosphate or adenosine 3':5'-cyclic monophosphate (cAMP) were much less effective in inducing acid tolerance, while the conversion of pH 7.0-grown log-phase cells to acid tolerance by pH 5.0 filtrates was inhibited by cAMP and bicarbonate. It seems likely that the acid tolerance response (acid habituation) involved the functioning of the extracellular protein(s) as protease reduces tolerance induction if added during acid habituation. Most inducible responses are believed to involve the functioning of only intracellular reactions and components; the present results suggest that this is not the case for acid habituation, as an extracellular protein (or proteins) is needed for induction.

Bacterial Proteins↗
PubMed1995

Preparation of white cell-reduced red cells by filtration: comparison of a bedside filter and two blood bank filter systems.

BACKGROUND: Concern has been raised about the quality of white cell (WBC)-reduced red cells (RBCs) obtained by bedside filtration. The bedside performance and workload of a routine bedside filter have been compared to the laboratory performance and workload of two blood bank filter systems. STUDY DESIGN AND METHODS: Buffy coat-depleted saline-adenine-glucose-mannitol (SAGM) RBCs (90 units) were prepared. Thirty units were filtered with each of the two blood bank filter systems, and 30 units were filtered (but not transfused) with the bedside filter in a clinical department after 8 to 24 days of storage. The RBCs lost and the postfiltration WBC content (Nageotte chamber) were determined for all filtered units, and the workload associated with filtration by each of the filter systems/filter was assessed. Units with a postfiltration content of > or = 2 x 10(6) WBCs were regarded as filtration failures. RESULTS: Four (13%) of the 30 units filtered at the bedside were filtration failures, compared to no failures with either of the blood bank filter systems. In addition, the median WBC content (0.14 x 10(6)) of the units filtered at the bedside (2 units/filter) was significantly higher than that of the units filtered in the blood bank (0.05 x 10(6)). The RBC loss was significantly higher with the filter systems than with the bedside filter, provided 2 units per filter were processed with the latter. The timed workload of the filter systems was 45 to 75 minutes per 12 units, which was similar to the time required for bedside filtration. CONCLUSION: Bedside filtration of 2 units of stored buffy coat-depleted SAGM RBCs per filter resulted in a higher incidence of filtration failure and higher postfiltration WBC content than did laboratory filtration of 1 unit of fresh buffy coat-depleted SAGM RBCs per filter with either of two blood bank filter systems.

Blood Component Removal↗
PubMedDate not supplied

Impact of various red cell concentrate preparation methods on the efficiency of prestorage white cell filtration and on red cells during storage for 42 days.

BACKGROUND: White cell (WBC) reduction prior to storage of red cell (RBC) concentrates may reduce the incidence of HLA alloimmunization and may improve the quality of stored RBCs. STUDY DESIGN AND METHODS: An integrated WBC-reduction filter system was tested after various RBC preparation procedures (from whole blood), and the influence of filtration on RBCs during storage for 42 days was investigated. Four additive system RBC preparation protocols were used. Units prepared from conventional triple blood bags were held for 4 to 6 hours at 22 degrees C, and then the RBCs were separated via a hard spin and filtration, performed immediately (Group 1) or after 18 hours' storage at 4 degrees C (Group 2). Units prepared from a top-and-bottom collection system were held at 22 degrees C for 4 to 6 or 22 to 24 hours; the centrifuged RBCs were filtered immediately after preparation (Groups 3 and 4, respectively, by holding time). WBC reduction and filtration time were analyzed. The impact of WBC filtration on pH, hemolysis rate, hemoglobin content, ATP, potassium glucose, and lactate was investigated weekly during storage for 42 days. RESULTS: Filtration reduced the mean WBC count by 3 to 4 log10, to 0.19 +/- 0.25 x 10(6), regardless of the RBC preparation method. Mean filtration times differed significantly between the groups and were longest for Group 1. Besides hemolysis and pH values, which were greater in all filtered units, no major differences were found in filtered and unfiltered RBCs during the storage interval. CONCLUSION: The efficiency of prestorage WBC filtration of RBCs was unaffected by the preparation procedure. However, the filtration time for RBCs freshly prepared in the conventional triple blood bag system without buffy-coat depletion was unacceptable. No major metabolic differences between filtered and unfiltered RBCs during 42 days of storage were found.

Blood Preservation↗
PubMed2002

Filtration treatment of dairy processing wastewater.

The effectiveness of various filtration agents in the primary treatment of dairy processing wastewater was investigated in laboratory-scale studies. The filtration agents used were: zeolite, crushed coral, charcoal, sand and crushed coral and sand and glass beads. The effectiveness of the filtration media was determined by testing parameters such as chemical oxygen demand (COD), total solids (TS) and total suspended solids (TSS) before and after filtration of wastewater. Percent reduction of the different parameters as a result of filtration was calculated. Sand combined with crushed coral or glass beads was found to be the most effective filtering medium with an average reduction of 99% in TSS, 93% in COD and 51% in TS. Charcoal filtration resulted in an average 85% reduction in TSS, 83% reduction in COD and 46% reduction in TS. Filtration using crushed coral resulted in an average 83% reduction in TSS, 78% reduction in COD and 39% reduction in TS. Zeolite was the least effective of the four media; it resulted in an average reduction of 78% in TSS, 76% in COD and 30% in TS. The differences among mean values of COD, TSS and TS after the different treatments were analyzed statistically using analysis of variance (ANOVA). When differences among means were found to be statistically significant (p < 0.0001), each mean value was compared with every other mean value using Duncan's multiple range test and least significant difference (LSD) test. Comparison of the mean values indicated the following: No significant difference between means of zeolite and crushed coral treatment. Mean values of COD, TSS, and TS of charcoal treatment were significantly different from the other treatments. Sand combined with crushed coral or glass beads was the most effective filtration agent and the means were significantly different from the means of the other treatments.

Agriculture↗
PubMed2004

Application of granular media filtration in wastewater reclamation and reuse.

Laboratory experiments were conducted at room temperature (20-25 degrees C) using four identical filter columns made of Plexiglas, each of 1 m height and 15 cm internal diameter, packed with granular media of 70 cm depth. Each filter was operated at a constant filtration rate, thus four rates were tested in the range of 2-15 m(3) m(-2) d(-1). Mono-media (sand) and dual-media (sand and anthracite) were tested and three types of municipal wastewaters, namely raw, primary and secondary-treated effluents were applied. The results obtained indicate that considerable improvements in effluent quality could be attained by tertiary sand filtration. Removal of solids, organics and bacteria was not significantly affected by the increase in filtration rate from 2 to 15 m(3) m(-2) d(-1). The highest removal efficiency was obtained at low filtration rate of 2 m(3) m(-2) d(-1), but higher filtration rates achieved acceptable removal efficiencies and provided effluents of good quality to satisfy the irrigation water quality standards. Since the conventional sand filters in wastewater treatment plants operate at a rate in the range of 2-5 m(3) m(-2) d(-1), utilization of high rate filtration is advantageous and would result in significant cost savings. However, with high filtration rates the filters require more frequent backwashing. Dual-media filters achieved 50% reductions in BOD suggesting that filtration could be used to treat primary effluents in emergency cases.

Bacteria↗
PubMed2001

Partial liquid ventilation reduces fluid filtration of isolated rabbit lungs with acute hydrochloric acid-induced edema.

BACKGROUND: Hydrochloric acid aspiration increases pulmonary microvascular permeability. The authors tested the hypothesis that partial liquid ventilation has a beneficial effect on filtration coefficients in acute acid-induced lung injury. METHODS: Isolated blood-perfused rabbit lungs were assigned randomly to one of four groups. Group 1 (n = 6) served as a control group without edema. In group 2 (n = 6), group 3 (n = 6), and group 4 (n = 6), pulmonary edema was induced by intratracheal instillation of hydrochloric acid (0.1 N, 2 ml/kg body weight). Filtration coefficients were determined 30 min after this injury (by measuring loss of perfusate after increase of left atrial pressure). Group 2 lungs were gas ventilated, and group 3 lungs received partial liquid ventilation (15 ml perfluorocarbon/kg body weight). In group 4 lungs, the authors studied the immediate effects of bronchial perfluorocarbon instillation on ongoing filtration. RESULTS: Intratracheal instillation of hydrochloric acid markedly increased filtration coefficients when compared with non-injured control lungs (2.3 +/- 0.7 vs. 0.31 +/- 0.08 ml.min(-1). mmHg(-1).100 g(-1) wet lung weight, P < 0.01). Partial liquid ventilation reduced filtration coefficients of the injured lungs (to 0.9 +/- 0.3 ml.min(-1).mmHg(-1).100 g(-1) wet lung weight, P = 0.022). Neither pulmonary artery nor capillary pressures (determined by simultaneous occlusion of inflow and outflow of the pulmonary circulation) were changed by hydrochloric acid instillation or by partial liquid ventilation. During ongoing filtration, bronchial perfluorocarbon instillation (5 ml/kg body weight) immediately reduced the amount of filtered fluid by approximately 50% (P = 0.027). CONCLUSIONS: In the acute phase after acid injury, partial liquid ventilation reduced pathologic fluid filtration. This effect started immediately after bronchial perfluorocarbon instillation and was not associated with changes in mean pulmonary artery, capillary, or airway pressures. The authors suggest that in the early phase of acid injury, reduction of fluid filtration contributes to the beneficial effects of partial liquid ventilation on gas exchange and lung mechanics.

Animals↗
PubMedDate not supplied

Theoretical comparison of filtration by the renal glomerulus and artificial membranes.

Improvement in filtration performance of artificial membranes will be possible if their structure mimics the renal glomerulus. Blood filtration with glomerular capillary and artificial membranes was, therefore, modeled to clarify the effects of their structure on filtration rates. Filtration rates were obtained by dividing membrane modules axially into a number of sections and using a calculus of finite differences. The modules were assumed to be composed of straight hollow fibers arranged in parallel, with a membrane surface area of 1.5 m2. The mean transmembrane pressure (TMP) was assumed to be too low for a protein gel layer to form on the membrane surface. A decrease in the inner diameter of membrane hollow fibers led to an increase in filtration rate because of an increased film mass transfer coefficient. A decrease in hollow fiber length also produced an increase in filtration rate because of decreased axial TMP drop. The glomerular capillary has a higher filtration rate than artificial membranes because of the low TMP drop and the low osmotic pressure at the membrane surface. Decreasing both the inner diameter and the length of the hollow fibers is effective in increasing the filtration rate at constant TMP.

Blood Flow Velocity↗
PubMed1982

Micropuncture study of changes in glomerular filtration and ion and water handling by the rat kidney during pregnancy.

1. In rats receiving 200 mul. min(-1) sodium chloride, glomerular filtration rate, single nephron glomerular filtration rate, and fractional reabsorption were measured at various points along the nephron, and ionic concentrations measured in early distal tubular fluid in virgin and 6, 12 and 19 day pregnant rats.2. Glomerular filtration increased progressively until the twelfth day of pregnancy. At 19 days of pregnancy the glomerular filtration rate, while still above virgin levels, was reduced below 12 day pregnant levels.3. Single nephron glomerular filtration rates measured in proximal and distal tubules were different at both 12 and 19 days of pregnancy, indicating an alteration of tubuloglomerular feed-back.4. A change in the ratio of glomerular filtration rate: distal single nephron filtration rate indicated a redistribution of glomerular filtrate to juxtamedullary nephrons by the sixth day of pregnancy.5. Fluid reabsorption is similar up to the early distal tubule but it is not possible to say whether reabsorption is the same in proximal tubules. More fluid is reabsorbed by late distal tubules and collecting ducts in 12 and 19 day pregnant animals than in the virgin and 6 day pregnant animals.6. Changes in ion reabsorption by the loop of Henle occurred during pregnancy; sodium reabsorption was increased by the sixth day of pregnancy and potassium reabsorption by the twelfth day.

Animals↗
PubMed1988

Effect of feeding on glomerular filtration rate and proteinuria in conscious aging rats.

Food intake increases glomerular filtration and proteinuria in adult rats. That this postprandial hyperfiltration could be age dependent was investigated in 3-, 10-, 20-, and 30-mo-old rats. Glomerular filtration rate and protein excretion were measured in fed or 24 h fasted conscious animals. In the 3-mo-old rats food ingestion increased renal filtration by 45% from 1.17 +/- 0.08 to 1.73 +/- 0.11 ml.min-1.g kidney wt-1 (n = 6). As the animals became older, the differences between fed and fasted periods became smaller: in 30-mo-old rats glomerular filtration rate was 0.85 +/- 0.03 and 1.01 +/- 0.06 ml.min-1.g kidney wt-1 (n = 6) in fasted and fed conditions, respectively. Proteinuria, which was mainly albuminuria, increased slightly with age and was more markedly reduced by acute food restriction in the 30-mo-old than in the 3-mo-old rats. Because the renin-angiotensin system activity decreases with age, its role in postprandial hyperfiltration was assessed by measuring glomerular filtration in 3-mo-old animals whose angiotensin II converting-enzyme activity was chronically inhibited by daily administration of perindopril. In such experimental conditions there was no longer a difference in renal filtration between fed and fasted rats. These data indicate that 1) postprandial increase in glomerular filtration is to some extent related to the renin-angiotensin system activity; 2) short-term reduction of food intake reduces proteinuria even in senescent rats, although the feeding dependence of the glomerular filtration is blunted with age.

Animals↗
PubMed2002

[Membrane filtration characteristics and its influencing factors in coagulation-microfiltration combination process for water purification].

A coagulation-microfiltration combination process was used to treat micro-polluted raw water in the intermittent operation mode. The effect of the operational parameters such as filtration time and aeration intensity, on the membrane filtration characteristics was investigated. An indicator J/p, defined as flux per unit pressure, was employed. At all the experimental conditions, J/p always fell down fast at first owing to membrane fouling, and then decreased slowly. But the initial decreasing rate and relative stable value of J/p in the latter period depended on the different operational parameters. J/p was greatly influenced by the filtration time, then the ratio of the filtration time to the ceasing time. Under the condition the filtration time was shortened by 1/2, the flux will increase by two times; when the ratio of filtration time/ceasing time was shortened, the flux was increased by only 50%. Higher J/p value could be achieved at the filtration time of 15 min and the ratio of filtration time/ceasing time of 3.8. Increased aeration intensity could enhance J/p to some extent. In the experiments, when the aeration intensity was increased from 2 to 4 m3/h, the membrane permeability was increased by about 15%; and the membrane permeability would not increased if the aeration intensity was continuously increased to 6 m3/h. Primary inorganic elements on the membrane surface at the present experimental condition were found to be Si and Ca from the element analysis.

Elements↗
PubMed2002

[Improvement in the dot immunogold filtration assay].

OBJECTIVE: To improve the filtrating unit of the dot immunogold filtration assay (DIGFA) to reduce its cost and make it suitable for fieldwork. METHODS: A thick round filtrating paper disc was made to replace the plastic filtrating box, and their results were compared. RESULTS: The size of the self-made filtrating paper disc was smaller and the cost was lower. The efficacy of antibody examination by our paper disc was the same as that of the usual plastic filtrating box. CONCLUSION: In some aspects, the round filtrating disc is better than the plastic filtrating box.

Animals↗
PubMed2006

[Nitrogen and phosphorus removal from septage filtrate in a ryegrass hydroponic system].

With hydroponic method, this paper studied the ryegrass Lolium multiflorum growth and its N and P removal under the application of septage filtrate. The results showed that a medium application rate of septage filtrate gave the highest yield of L. multiflorum. The N and P removal in the ryegrass hydroponic system was increased with increasing application rate of septage filtrate, but the water quality was declined when super high volume of septage filtrate was added. The N and P uptake by L. multiflorum had no significant difference under medium, high, and super high application rate of septage filtrate, with the maximum uptake of N and P being 13.6 g x m(-2) and 3.17 g x m(-2) respectively. The removed proportion of N and P through ryegrass uptake declined w ith increasing septage filtrate application rate. Under the same total load, increasing the application frequency of septage filtrate could improve ryegrass yield, water quality, and nutrients removal. To select an appropriate application rate and frequency of septage filtrate was the key in improving the nutrients removal efficiency of ryegrass hydroponic system.

Biodegradation, Environmental↗
PubMed1991

[The recovery of the kidney filtration functional reserve in diabetes mellitus patients on captopril treatment].

Overall 42 normotensive patients suffering from type I diabetes mellitus without proteinuria were examined for the effect of hyperfiltration on renal glomerular function and for changes in glomerular function seen during medicamentous treatment of hyperfiltration. Glomerular function was evaluated from the basal level of glomerular filtration (GF), the status of filtration reserves (i. e. according to the dynamics of the GF level in response to oral protein administration), and from the magnitude of albuminuria. Three groups of diabetes mellitus patients were distinguished: with filtration reserves, with decreased filtration reserves, and with no reserves. All the three groups did not differ in the age, diabetes standing or the degree of carbohydrate disorders compensation (HBA1c). Still, the patients with no filtration reserves significantly differ from the other groups with a high level of GF and albuminuria. In 9 patients, a study was made of the effect produced by captopril (an inhibitor of the angiotensin-transforming enzyme) on filtration reserves and albuminuria. After 3 to 6 months of the treatment five patients with no filtration reserves manifested a fall of the basal level of GF down to normal, the recovery of filtration reserves, and a decline of albuminuria. It is assumed that elimination of hyperfiltration due to the treatment with the inhibitors of the angiotensin-transforming enzyme may be an effective means of diabetic nephropathy prevention.

Adolescent↗
PubMed1997

[Effect of whole blood preparation and leukocyte filtration on storage of erythrocyte concentrates over 42 days].

Leukocyte reduction prior to storage of red cell concentrates (RCC) may reduce the incidence of HLA alloimmunization and may improve the quality of stored RCC. We tested an RCC leukoreduction filter system (Baxter) with an integrated Pall RCM-1 filter and investigated the filtration efficiency and the impact on red cells during storage for 42 days after different whole-blood preparation procedures. After whole-blood donation, all units (n = 9, +6 unfiltered controls per group) were either stored at 22 degrees C for up to 6 h (groups 1, 2, 3) or for 24 h (group 4) RCC were either prepared from a triple blood bag system (PL 146, groups 1, 2) or were buffy-coat-depleted (PL 2209, groups 3, 4). Groups 1, 3 und 4 were filtered immediately, whereas group 2 was stored another 18 h at 4 degrees C before filtration. Filtration efficiency and filtration time were determined. Hemolysis, ATP, 2,3-diphosphoglycerate (2,3-DPG), glucose, electrolytes, lactate, hematocrit, Hb and pH were quantified weekly. White blood cells (WBC) were reduced by 3-4 log10 to 0.1-0.3 x 10(6) (mean) by filtration (all groups) regardless of the RCC preparation. Mean filtration times were 1 h 36 min, 33 min, 29 min, and 18 min for the groups 1 to 4, respectively. There were no major differences for the in vitro storage values except for hemolysis and pH, which were elevated in all filtered units, and potassium, which was elevated in the unifiltered units. In conclusion, prestorage leukocyte filtration of RCC reduced the WBC by 3-4 log10, whereas the extended filtration time was a major disadvantage.

2,3-Diphosphoglycerate↗
PubMed2000

Schlemm's canal becomes smaller after successful filtration surgery.

OBJECTIVE: To determine whether filtration surgery causes secondary changes in the trabecular meshwork and Schlemm's canal. Successful filtration surgery allows most aqueous outflow to enter the filtration bleb, bypassing the meshwork and canal, and may result in underperfusion of these structures. METHODS: Eyes with primary open-angle glaucoma (POAG) that had undergone filtration surgery were studied and compared with eyes with POAG that had not undergone surgery. In addition, normal eyes and eyes with pseudoexfoliative glaucoma were studied for comparison. The trabecular meshwork and Schlemm's canal were examined by light and electron microscopy. RESULTS: Schlemm's canal was significantly smaller in eyes with POAG after filtration surgery than in normal eyes (canal width, 178 +/- 71 microm vs 276 +/- 52 microm; P<.001) or in eyes with medically treated POAG of similar clinical severity (261 +/- 60 microm, P =. 03). The decrease in canal size seemed to be related to the success of the filtration procedure, since eyes with blebs and low pressures had the smallest canals. Eyes with medically treated POAG at earlier clinical stages of glaucoma did not have a significant decrease in canal size when compared with normal eyes. Eyes with advanced pseudoexfoliative glaucoma had canal widths 20% smaller than those in normal eyes (P =.08). CONCLUSIONS: Filtration surgery was associated with a decrease in the size of Schlemm's canal, most likely due to underperfusion of the meshwork. A significant decrease in canal size is otherwise not a finding in POAG. In contrast, the canal tended to become smaller in advanced cases of pseudoexfoliative glaucoma. CLINICAL RELEVANCE: The decrease in size of Schlemm's canal after successful filtration surgery could make glaucoma more difficult to control if the filter ultimately fails. Arch Ophthalmol. 2000;118:1251-1256

Aged↗