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PubMedDate not supplied

Capillary filtration in venous hypertension. Comparison between the vacuum suction chamber (VSC) device and straingauge phlethysmography.

To evaluate capillary filtration a group of normal subjects and two groups of subjects with venous incompetence (50 with deep and 50 with superficial incompetence) were studied with the vacuum suction chamber (VSC) device applied onto the internal perimalleolar region. This method was compared with straingauge plethysmography rate of ankle swelling (RAS). By the VSC the time taken for the weal to disappear (VSC time) was considered indicative of capillary filtration. The values obtained with the two methods were well related (r < 0.742) and there was a good separation between patients and normals. The separation between the two groups of patients was significantly better (p < 0.05) with the VSC time. In conclusion VSC time is a good indication of capillary filtration in comparison with straingauge plethysmography RAS. It may be used to assess variations in capillary filtration in venous hypertension and possibly to follow up the effects of treatments.

Adult↗
PubMedDate not supplied

Factors in biological fluids affect gel filtration behavior of epidermal growth factor.

There have been conflicting reports on the presence of multiple forms of epidermal growth factor (EGF) in human saliva. The present study was initiated to study the gel filtration behavior of EGF in saliva and other biological fluids. In addition, studies were performed to determine if there were factors in saliva or other biological fluids that would influence the gel filtration behavior of EGF. Gel filtration studies with saliva and urine demonstrated EGF migration consistent with a molecular weight of 35 kDa with no heterogeneity observed. The addition of radiolabeled EGF to either saliva or urine resulted in an altered migration on gel filtration. These results provide evidence for a protein-peptide interaction in saliva and other biological fluids that alters the apparent physical properties of mature EGF.

Chromatography, Gel↗
PubMed2002

[Transcapillary filtration of plasma proteins in patients with diabetes type II microangiopathy complications].

UNLABELLED: This study presents the results of the research on transcapillary filtration of plasma proteins in patients with non-insulin dependent diabetes mellitus (NIDDM). The aims of the study were as follows: (a) Examination of transcapillary filtration of plasma proteins in patients with NIDDM; (b) Search for correlations between metabolic status of diabetes, severity of diabetic microangiopathy and penetration of individual protein fractions into the blister fluid; (c) Examination of the influence of nonenzymatic glycation on albumin fragmentation and its transcapillary filtration. It was also decided to check whether changes in the blister fluid would appear earlier than fundal fluorescein angiography or microalbuminuria, two markers of diabetic microangiopathy. The study enrolled 34 patients with type II diabetes mellitus, aged 35-78 years, with a mean disease duration of 12.5 years (SD = 7.8). The control group included 10 non-diabetic volunteers aged 31-76 years. The mean age in both groups did not differ significantly. The cantharidin blister method was used to study the permeability of capillary vessels. The following laboratory tests were done: concentrations of serum urea, creatinine, glucose, fructosamine, glycated hemoglobin, cholesterol, and triglycerides. Electrophoretic separation of proteins in plasma and blister fluid was performed and the concentration of fructosamine in fluid was measured. Routine urinalysis was supplemented with microalbuminuria. The eye fundus was inspected and fundal fluorescein angiography was done. The influence of nonenzymatic glycation on protein fragmentation and its possible impact on the permeability of capillary vessels was determined with in vitro glycation of human serum albumin. In patients without diabetic retinopathy the Cb:Cs ratio for beta-globulin turned out to be significantly lower than in patients with proliferative retinopathy. Patients with normoalbuminuria had the Cb:Cs ratio for alpha 2-globulin significantly lower than patients with urinary albumin concentrations > or = 165 mg/L. When the group was divided with regard to serum fructosamine concentrations, the subgroup with fructosamine concentrations lower than 3 mmol/L revealed a significantly higher Cb:Cs ratio for fructosamine than the subgroup with fructosamine > or = 3 mmol/L. Concentrations of total protein, albumin, beta-globulin and gamma-globulin in blister fluid correlated positively with glycemia in the control group. Blister fluid concentration of beta-globulin correlated positively with HbAIC concentration. In the study group, total protein content in blister fluid correlated negatively with duration of diabetes and level of glycosuria. Concentrations of blister fluid alpha 1-globulin and gamma-globulin correlated negatively with glycosuria. Concentrations of blister fluid beta-globulin correlated negatively with duration of diabetes. Electrophoretic separation of in vitro SDS glycosylated human serum revealed no additional fraction in the incubated samples. Electrophoretic separation of in vitro glycosylated albumin disclosed co-migration of albumin monomers incubated for varying times with glucose. CONCLUSIONS: 1. Glycation of human serum and albumin does not cause fragmentation of the proteins, but decreases transcapillary filtration of albumin due to change of molecular electric charge. 2. Patients with non-insulin dependent diabetes and microangiopathic complications reveal increased transcapillary transport of alpha 2- and beta-globulin in skin. 3. Increased permeability of skin capillary vessels for alpha 2- and beta-globulin in diabetic microangiopathy reflects an advanced stage of the disease and may facilitate progression.

Adult↗
PubMed1992

Acute effects of hydroxyethylrutosides on capillary filtration in normal volunteers, patients with venous hypertension and in patients with diabetic microangiopathy (a dose comparison study).

The acute effects of hydroxyethylrutosides on capillary filtration were studied in 12 normal subjects, 25 patients with venous hypertension and 22 diabetics with microangiopathy. The two groups of patients randomly received a single oral dose (500 or 1000 mg) of hydroxyethylrutosides. A single dose of 500 mg was used for normal volunteers. In the following 6 hours capillary filtration was studied with straingauge plethysmography. The decrease in capillary filtration was evident within the first hour and was at its peak between the second and fourth hour. After 6 hours it was still significantly below baseline values in patients. The 1000 mg dose was significantly more effective in both groups of patients. This study confirms the efficacy of hydroxyethylrutosides in decreasing capillary filtration. It suggests that the effect of one dose lasts at least 6 hours and also that the higher dose is more effective.

Adult↗
PubMed1990

[The laser surgery of cystic filtration pads].

The paper describes results after treatment of 12 patients with cystic filtration cushions formed after antiglaucomatous operations. Two methods were used: introduction, into the cystic filtration cavity, of either autologous blood or serum of autologous blood stained by sodium fluorescein solution with subsequent coagulation by argon laser radiation, energy 0.2-0.4 wt, spot diameter 200-500 mem, exposition time 0.2-0.3 sec. The number of applied coagula depended on the size of a cystic filtration cushion. The results of treatment, followed up within a year, have shown formation of a filtration cushion of a vague type, appearance of stabilization of intraocular pressure and visual functions in all patients.

Aged↗
PubMedDate not supplied

Bronchoalveolar lavage fluid processing. Effect of membrane filtration preparation on neutrophil recovery.

Two common methods for the preparation of bronchoalveolar lavage (BAL) fluid for cytologic examination, cytocentrifugation and membrane filtration, have been found to yield different results in the quantitation of lymphocytes. To compare these two methods for the quantitation of neutrophils, the differential counts from 640 consecutive clinical specimens were analyzed retrospectively. The percentage of neutrophils resulting from the preparation of the BAL fluids by the two methods were highly correlated (r2 = .72). However, cytocentrifugation yielded consistently higher neutrophil percentages than did membrane filtration (means for all samples: 18.5 +/- 1.0% vs. 14.7 +/- 0.9%; P less than .001). To investigate the source of the variation in neutrophil quantitation by the two methods, two series of mixing experiments were performed in which neutrophil-rich cell suspensions were added to BAL fluids. Determination of the cellular differentials before and after mixing the cell suspensions demonstrated that membrane filtration preparation tends to lose neutrophils while cytocentrifugation accurately recovers neutrophils. Thus, accurate quantitation of the two cells recovered by BAL may require use of both cytocentrifugation and membrane filtration.

Adult↗
PubMed1989

Effects of Moraxella bovis and culture filtrates on 51Cr-labeled bovine neutrophils.

The cytotoxicity of Moraxella bovis whole cells and culture filtrates was studied, using 51Cr-labeled bovine and human blood neutrophils. The cytotoxicity of living M bovis was directly related to the concentration of bacteria in the neutrophil cultures, and was maximal at an approximate neutrophil to bacteria ratio of 1:10. Cytotoxicity was maximal by 30 minutes after living bacteria were added to the suspension of the 51Cr-labeled neutrophils. Expression of the cytotoxicity was dependent on the presence of Ca2+ in the media, and was independent of the presence of Mg2+. Cytotoxic activity was eliminated by inactivating M bovis in buffers containing formalin or sodium azide. Hemolytic and nonhemolytic isolates of M bovis were examined for cytotoxic activity. All 7 of the hemolytic isolates were cytotoxic for bovine neutrophils, but all 4 of the nonhemolytic isolates were devoid of cytotoxic activity. None of the 11 isolates were cytotoxic for human neutrophils. Sterile filtrates from 6-hour shaker cultures of a hemolytic M bovis isolate were cytotoxic for bovine neutrophils. Cytotoxicity of the filtrate was eliminated by heating, incubation with trypsin, or addition of EDTA to the media. Bacterial homogenates or sterile filtrates prepared from statistically incubated cultures of M bovis were not toxic for bovine neutrophils.

Animals↗
PubMedDate not supplied

The effects of hydropenia, volume expansion, interstitial pressures, excluded volumes, and venous pressures on the robustness of capillary filtration coefficient determination.

The measurement of peripheral capillary filtration coefficient (Kf) by venous occlusion methods presupposes that filtration equilibrium does not occur along the length of the filtering surface, since this would result in an unpredictably low estimate for Kf. Filtration equilibrium occurs if the ratio of plasma flow (Q) to Kf is less than a critical value previously estimated to be between 200 and 250 mmHg. The minimum Q/Kf was reevaluated, taking into account the nonlinear relationship between protein concentration and oncotic pressure, changes in interstitial fluid hydrostatic and oncotic pressure, interstitial excluded volume, whether hydropenia or volume expansion is present, and whether the induced venous pressure change is low (10 mmHg) or high (40 mmHg). In all conditions the minimum Q/Kf ranged from 10 to 20 mmHg, while experimental conditions commonly have Q/Kf ratios from 1200 to 1500 mmHg. Thus, filtration equilibrium is unlikely to occur during Kf determinations under any circumstances in a living organism. Kf methodology is considerably more robust than previously reported.

Animals↗
PubMed1986

Local regulation of subcutaneous blood flow and capillary filtration in limbs with occlusive arterial disease. Studies before and after arterial reconstruction.

The aim of the study was to examine the local blood flow regulation and the capillary filtration rate in patients with occlusive arterial disease before and after arterial reconstructive surgery. Fourty-seven normal subjects and 99 patients were studied. Subcutaneous blood flow was measured on the forefoot by the local 133Xenon method. Forefoot arterial blood pressure was measured indirectly by cuff and strain-gauge technique. Capillary filtration rate was measured by strain-gauge plethysmography on the forefoot. The arterial and venous pressures of the forefoot were changed by elevating or lowering the foot in relation to heart level. In normal limbs autoregulation was demonstrated during elevation of the limb when blood flow remained almost constant despite the reduction in arterial and perfusion pressures. The local vasoconstrictor response to increased venous transmural pressure was demonstrated when the limb was lowered and blood flow decreased about 30% despite a constant perfusion pressure. In limbs with occlusive arterial disease both local blood flow regulation mechanisms became progressively more abnormal the severe the symptoms and the lower the distal blood pressure. Estimations of the changes in local vascular resistance suggested that the abnormalities in blood flow regulation in all but the severest cases are the result of changes in local perfusion pressure rather than the result of inability of the arteriolar smooth muscle to dilate and constrict in response to changes in arterial and venous pressures. After arterial reconstruction the two mechanisms generally normalized within about a week. However, disturbances occurred in some cases in the early postoperative period, possibly as the result of postoperative pain and stress. Postreconstructive hyperaemia developed in most limbs despite the early normalization of local blood flow regulation. Compared with normal limbs, the forefoot capillary filtration rate was reduced in limbs with occlusive arterial disease. In the early postoperative period the filtration rate remained reduced, but it increased to normal values within three months. Postreconstructive oedema developed independently of the normalization of blood flow regulation, and almost exclusively after femoro-distal by-pass surgery. The study supports the hypothesis that the postreconstructive oedema is a lymphoedema due to surgical trauma, rather than the result of microvascular derangement.

Adult↗
PubMedDate not supplied

[Transcapillary filtration of electrolytes in the brain after craniocerebral injuries].

A new method was used to determine the value and direction of electrolyte filtration through the walls of capillaries in the brain in patients with craniocerebral injury. It was found that the period of the development of brain edema coincided in time with the prevalence of the processes of sodium, calcium, and fluid escape from the cerebral vessels into the cerebral tissue. The movement of potassium through the capillary wall was counter-current to that of sodium filtration in most cases. Transcapillary filtration of electrolytes in patients with craniocerebral injury during the posttraumatic period was characterized by recurrent changes in the direction of filtration. Electrolytes (sodium, potassium, and calcium) possess their own, often independent of one another, mechanisms of transfer through the membranes of the histohematic barriers.

11-Hydroxycorticosteroids↗
PubMed1979

Distribution of interstitial compliance and filtration coefficient in canine lung.

Utilizing a modification of the isogravimetric methodology, we have estimated the perivascular interstitial compliance and filtration coefficient in the canine lung. These values averaged 1.8 g/cm H2O and 34 (g/h)/cm H2O, respectively, per 100 g lung wet weight. By studying lungs at both low and high states of inflation (where the alveolar septae are collapsed) we were also able to determine the spatial distribution of both the interstitial compliance and filtration coefficient. We estimate that of the above total interstitial compliance a maximum of 55% is around alveolar septal vessels, 20% around extra-alveolar arteries and 25% around extra-alveolar veins. Of the above total filtration coefficient, 50% represents filtration from alveolar septal vessels, 23% from extra-alveolar arteries, and 27% from extra-alveolar veins. Our results imply that there are finite interstitial compliances communicating with all permeable vessels. Significant pressures can be built up in these spaces, thereby acutely limiting the further formation of interstitial edema.

Animals↗
PubMed1983

Membrane filters and membrane-filtration processes for health care.

The development of membrane-filtration processes is reviewed, and current types and uses of membrane filtration in health care is discussed. Development of adequate support structures for filters and of disposable filtration devices has facilitated development of filtration processes for pharmaceutical industry, manufacturing in hospital pharmacies, and direct patient care. Hydrophobic filters have also been developed; aqueous solutions cannot wet the pore structures of these filters and therefore cannot pass. Sterility-testing systems have also been developed. There are two types of filters: depth (constructed of compacted fibers) and membrane (which have a homogeneous internal structure). Depth filters retain only a portion of particles in a particular size range and are generally not acceptable for use in health care. Membrane filters retain all particles of a given size. Types of membrane filters are selected for specific uses based on needed flow rates, particulate load, and retention capability. Membrane filters may be validated using bacterial-passage, bubble-point, and diffusion tests. Most membrane filters used in health care are microporous filters that retain particles in the 0.1-10-micron size range. Applications are currently being developed for ultrafilters, which retain both particles and substances with large molecular structures such as proteins, and reverse-osmosis filter membranes, which allow only water or water-miscible solvents of very low molecular weights to pass. Experience in engineering designs, quality assurance, and test procedures has led to the development of many safe, reliable, and effective membrane products for health care.

Micropore Filters↗
PubMed1983

[Methodological survey of erythrocyte filtration time].

We measured the whole blood filtration time of 30 healthy subjects. The influence of hematocrit, fibrinogen, leucocyte and platelet count on filtration time was also evaluated. Multiple regression analysis did not demonstrate any effect of the above-mentioned parameters when they were separately considered. We have subsequently taken from the entire population a group of 14 subjects in which were simultaneously found values of hematocrit greater than or equal to 41%, fibrinogen greater than or equal to 210 mg/100 ml and platelet count greater than or equal to 250,000/mm3. The filtration time was significantly higher in this group (69 +/- 4 sec) than in the remaining 16 normal subjects (56 +/- 4 sec), p less than 0.05. These data suggest that the simultaneous variation of several parameters could modify the whole blood filtration time, while these parameters have no effect when taken separately.

Adult↗
PubMed1984

Focal pressure: a new method to encourage filtration after trabeculectomy.

One cause of failure of trabeculectomy is early closure of the sclerostomy with insufficient aqueous outflow and subsequent scarring of Tenon's capsule and conjunctiva. Ocular massage and other forms of manipulation of the scleral flap have been used in the past to enhance filtration in cases where full-thickness filtration procedures were performed, and they have been suggested for use with trabeculectomy as well. The authors propose a new method in which focal pressure is applied with an anesthetic-moistened applicator directly to the conjunctiva beside the edge of the scleral flap. This appears to be particularly indicated in trabeculectomy, and has both theoretical and practical advantages over the conventional forms of enhancing filtration in eyes having been treated with trabeculectomy. In 17 of 18 cases having trabeculectomy according to Watson's technique and in which it appeared that no filtration would develop in the postoperative period, focal pressure was successful in creating a satisfactory bleb.

Aqueous Humor↗
PubMed1982

Glomerular immune complex formation and induction of lymphoma in athymic nude mice by tissue filtrates of Crohn's disease patients.

Lymph nodes and intestinal filtrates from Crohn's disease patients produced lymphoma in five and plasma cell hyperplasia in two of 63 athymic (nu/nu) mice. None of 27 mice injected with intestinal filtrates from ulcerative colitis patients but one of 13 mice injected with normal-appearing colon developed lymphoma. With an indirect immunofluorescence technique, sera from all nine patients with symptomatic Crohn's disease and one of 15 patients with asymptomatic Crohn's disease demonstrated cytoplasmic immunofluorescence in a lymphoma produced by Crohn's disease filtrates, but not in a control filtrate-induced lymphoma. None of 46 sera from ulcerative colitis patients or control subjects demonstrated immunofluorescence. In addition, immunofluorescent staining with symptomatic Crohn's disease sera recognized an antigen(s) within glomeruli that were also stained with anti-mouse IgG and IgM. Kidneys from the control mice did not show any staining. These studies suggest that an agent present in lymph nodes and intestine of patients with Crohn's disease can induce lymphoma and glomerular immune complexes in nu/nu mice.

Animals↗
PubMed1981

Gas-chromatographic assay of free phenytoin in ultrafiltrates of plasma: test of a new filtration apparatus and specimen stability.

I describe a gas-chromatographic procedure involving a nitrogen detector for "free" (or "unbound") phenytoin in the concentration range 0.2-4.0 mg/L in ultrafiltrates of plasma. The CV (n = 10) for the assay was 2.9% for a 0.49 mg/L concentration, 1.5% for 2.02 mg/L. The sensitivity was 0.05 mg/L. The ultrafiltration process ("Ultra-Free" filters) used to separate the free phenytoin fraction from the bound fraction was tested. The mean of and CV for free phenytoin concentrations measured in eight replicate serum filtrates were 0.68 mg/L and 15%; for eight replicate plasma filtrates the values were 0.42 mg/L and 2.9%. Thus serum is not suitable for this procedure. Storage of plasma before filtration under a wide variety of times and temperatures has an insignificant effect upon the filtration process. Some evidence was found of occasional protein "leakage" through the filters.

Chromatography, Gas↗
PubMedDate not supplied

Induction and detection of delayed dermal hypersensitivity in guinea-pig immunized with Blastomyces dermatitidis lysate and filtrate antigens.

Guinea-pigs were immunized using yeast phase antigens (lysate and filtrate preparations) from two strains of Blastomyces dermatitidis (T-58 and Le). Following a sensitization period, the animals were skin tested on days 40 and 216 using T-58 and Le yeast and mycelial phase lysate and filtrate antigen preparations for the detection of delayed dermal hypersensitivity (DTH). Using the Friedman's analysis of variance by rank test, significant differences were found in the efficacy of the immunogens to induce DTH in the animals when skin tested on both occasions (P < 0.05). Optimal reactivity was observed in guinea-pigs immunized with Le yeast lysate (mean axes of induration ranging from 12.0 to 18.8 mm and 7.0 to 18.5 mm on day 40 and 216, respectively) and T-58 yeast filtrate (mean axes of induration ranging from 7.5 to 18.0 mm and 8.0 to 17.0 mm on day 40 and 216, respectively) when the immunogens were administered with adjuvant. When the same data was analysed using the Friedman's test with regard to evaluating the efficacy of the skin test antigens to detect DTH, significant differences were found between them (P < 0.05) with optimal results using the Le mycelial filtrate and yeast lysate antigens (mean axes of induration ranging from 7.0 to 16.5 mm and 7.5 to 14.5 mm, respectively) when skin testing was done on day 40. When skin testing was done on day 216, the T-58 and Le mycelial lysate antigens gave optimal results (mean axes of induration ranging from 9.0 to 18.5 mm and 7.5 to 15.0 mm, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adjuvants, Immunologic↗
PubMed1994

[Clinical observation and management of the filtration bleb after trabeculectomy].

The author reports 42 patients (56 eyes) of glaucoma performed trabeculectomy under operating microscope from August 1991 to April 1993. After operation the conjunctival filtration blebs were observed in details. The formation rate of ideal blebs was 80.3%. The success rate of operation was 87.5%. The author discusses the mechanisms of lowered intraocular pressure in trabeculectomy and the relation between the type of filtration bleb and intraocular pressure. The author believes that the formation of functional subconjunctival filtration blebs is the key to successful operation. The management of non-functional filtration blebs is presented in this paper.

Adolescent↗